Choose the best answer:
Teachers provide a model for children to _________.

 

Read the following passage and choose the best answer (A, B, C, D):
A satellite is best understood as a projectile, or an object that has only one force acting on it — gravity. Technically speaking, anything that crosses the Karman Line at an altitude of 100 kilometers (62 miles) is considered in space. However, a satellite needs to be going fast — at least 8 km (5 miles) a second — to stop from falling back down to Earth immediately. If a satellite is traveling fast enough, it will perpetually “fall” toward Earth, but the Earth’s curvature means that the satellite will fall around our planet instead of crashing back on the surface. Satellites that travel closer to Earth are at risk of falling because the drag of atmospheric molecules will slow the satellites down. Those that orbit farther away from Earth have fewer molecules to contend with. There are several accepted “zones” of orbits around the Earth. One is called lowEarth-orbit, which extends from about 160 to 2,000 km (about 100 to 1,250 miles). This is the zone where the ISS orbits and where the space shuttle used to do its work. In fact, all human missions except for the Apollo flights to the moon took place in this zone. Most satellites also work in this zone. Geostationary or geosynchronous orbit is the best spot for communications satellites to use, however. This is a zone above Earth’s equator at an altitude of 35,786 km (22,236 mi). At this altitude, the rate of “fall” around the Earth is about the same as Earth’s rotation, which allows the satellite to stay above the same spot on Earth almost constantly. The satellite thus keeps a perpetual connection with a fixed antenna on the ground, allowing for reliable communications. When geostationary satellites reach the end of their life, protocol dictates they’re moved out of the way for a new satellite to take their place. That’s because there is only so much room, or so many “slots” in that orbit, to allow the satellites to operate without interference. While some satellites are best used around the equator, others are better suited to more polar orbits — those that circle the Earth from pole to pole so that their coverage zones include the north and south poles. Examples of polar-orbiting satellites include weather satellites and reconnaissance satellites  
4. The word “took place” in the third paragraph could be best replaced by __________.

Read the following passage and choose the best answer (A, B, C, D):
People have been donating blood since the early twentieth century to help accident victims and patients undergoing surgical (1)_____. Usually a pint of whole blood is donated, and it is then divided into platelets, white blood cells, and red blood cells. People can donate blood (for red blood cells) about once every two months. (2) ____ the blood from the donor to the recipient is straightforward. It involves (3) _____ the blood from a donor’s arm vein by means of a hypodermic syringe. The blood flows through a plastic tube to a collection bag or bottle (4)_______ contains sodium citrate, which prevents the blood from clotting. When the blood is given to a patient, a plastic tube and hypodermic needle are connected to the recipient’s arm. The blood flows down from the container by gravity. This is a slow process and may last as long as 2 hours to complete the infusion of blood into the recipient. The patient is protected (5)______ being infected during the transfusion. Only sterile containers, tubing, and needles are used, and this helps ensure that transfused or stored blood is not exposed to disease causing bacteria

Read the following passage and choose the best answer (A, B, C, D):
Social networking sites such as Facebook and MySpace do not help you make more  genuine close friends, according to a survey by researchers who studied how the websites are changing the nature of friendship networks. Although social networking on the internet helps people to collect hundreds or even thousands of acquaintances, the researchers believe that face to face contact is nearly always necessary to form truly close friendships.  “Although the numbers of friends people have on these sites can be massive, the actual number of close friends is approximately the same in the face to face real world,” said psychologist Will Reader, from Sheffield Hallam University. Social networking websites such as Facebook, Bebo and MySpace have taken off rapidly in recent years. Facebook was launched initially in 2004 for Harvard University members but has since expanded to more than 34 million users worldwide. MySpace, which was set up in 2003, has more than 200 million users and was bought by Rupert Murdoch’s News Corporation in 2005 for $580m (£285m). Previous research has suggested that a person’s conventional friendship group consists of around 150 people, with five very close friends but larger numbers of people whom we keep in touch with less regularly. This figure is so consistent that scientists have suggested it is determined by the cognitive constraints of keeping up with large numbers of people. But Dr. Reader and his team have found that social networking sites do allow people to stretch this figure. The team asked more than 200 people to fill in questionnaires about their online networking, asking for example how many online friends they had, how many of these were close friends and how many they had met face to face. The team found that although the sites allowed contact with hundreds of acquaintances, as with conventional friendship networks, people tend to have around five close friends. Ninety per cent of contacts whom the subjects regarded as close friends were people they had met face to face. “People see face to face contact as being absolutely imperative in forming close friendships,” added Dr. Reader. He told the British Association Festival of Science in York that social networking sites allow people to broaden their list of nodding acquaintances because staying in touch online is easy. “What social network sites can do is decrease the cost of maintaining and forming these social networks because we can post information to multiple people,” he said.  But to develop a real friendship we need to see that the other person is trustworthy, said Dr. Reader. "What we need is to be absolutely sure that a person is really going to invest in us, is really going to be there for us when we need them … It’s very easy to be deceptive on the internet."
5. According to the passage, Dr. Reader and his team have found that _______________

Read the following passage and choose the best answer (A, B, C, D):
Far from being barren wastelands, deserts are biologically rich habitats with a vast  array of animals and plants that have adapted to the harsh conditions there. Some deserts are among the planet’s last remaining areas of total wilderness. Yet more than one billion people, one-sixth of the Earth’s population, actually live in desert regions.  Deserts cover more than one fifth of the Earth’s land, and they are found on every continent. A place that receives less than 10 inches (25 centimeters) of rain per year is considered a desert. Deserts are part of a wider classification of regions called “dry lands.” These areas exist under a moisture deficit, which means they can frequently lose more moisture through evaporation than they receive from annual precipitation.  And despite the common conceptions of deserts as dry and hot, there are cold deserts as well. The largest hot desert in the world, northern Africa’s Sahara, reaches temperatures of  up to 122 degrees Fahrenheit (50 degrees Celsius) during the day. But some deserts are always cold, like the Gobi desert in Asia and the desert on the continent of Antarctica. Others are mountainous. Only about 10 percent of deserts are covered by sand dunes. The driest deserts get less than half an inch (one centimeter) of precipitation each year, and that is from condensed fog not rain.  Desert animals have adapted ways to help them keep cool and use less water. Camels, for example, can go for days without food and water. Many desert animals are nocturnal, coming out only when the brutal sun has descended to hunt. Some animals, like the desert tortoise in the south-western United States, spend much of their time underground. Most desert birds are nomadic, crisscrossing the skies in search of food. Because of their very special adaptations, desert animals are extremely vulnerable to introduced predators and changes to their habitat.  Some of the world’s semi-arid regions are turning into desert at an alarming rate. This process, known as “desertification,” is not caused by drought, but usually arises from the demands of human populations that settle on the semi-arid lands to grow crops and graze animals. The pounding of the soil by the hooves of livestock may degrade the soil and encourage erosion by wind and water.
5. What may make the diversity of deserts’ plants and animals poorer?

Choose the best answer:
Mukai Chiaki, the first female Japanese astronaut, ……….. 15 days aboard the space shuttle Columbia in space before it …….. to the Earth on July 23,1994.

Read the following passage and choose the best answer (A, B, C, D):
The idea of going overseas to study can be daunting, with visions of baffling languages or nights spent in isolation while you are gradually forgotten by your friends and family. (1) _________, the benefits of studying abroad - such as broadening your mind, improving your career prospects and making friends from all over the world - can make digging out your passport really rewarding. “Studying abroad is an eye-opening experience,” says Anna Boyd, event manager at The Student World. “Being (2) _________ in another culture, understanding differences and spotting similarities, living on a beach or in the mountains, (3) _________ will have an impact on every student.” Overseas study comes in many shapes and sizes. It might be a single semester abroad via an Erasmus programme, for example. Or you might elect to follow a full three- or fouryear degree programme. Whatever your ambition, the key is starting early. Some countries require specific combinations of A-levels from UK students. Germany looks for four A-levels including maths or science and one modern foreign language, for instance, while others, such as the US, value extracurricular activities. Starting our research well ahead (4) _________ time can help you make the right choices. “Getting involved in sports, arts and music is also worth considering, as well as gaining experience through volunteering and work placements,” says Boyd. In fact, applying to study abroad could even work to your advantage , for example, you might encounter lower (5) _______ requirements

Read the following passage and choose the best answer (A, B, C, D):
Esperanto is what is called a planned, or artifiial, language. It was created more than a century ago by Polish eye doctor Ludwik Lazar Zamenhof. Zamenhof believed that a common language would help to alleviate some of the misunderstandings among cultures. In Zamenhof's fist attempt at a universal language, he tried to create a language that was as uncomplicated as possible. This fist language included words such as ab, ac, ba, eb, be, and ce.This did not result in a workable language in that these monosyllabic words, though short, were not easy to understand or to retain. Next, Zamenhof tried a different way of constructing a simplified language. He made the words in his language sound like words that people already knew, but he simplifid the grammar tremendously. One example of how he simplifid the language can be seen in the suffies: all nouns in this language end in o, as in the noun amiko, which means "friend", and all adjectives end in -a, as in the adjective bela, which means "pretty". Another example of the simplifid language can be seen in the prefi mal-, which makes a word opposite in meaning;theword malamiko therefore means "enemy", and the word "malbela" therefore means "ugly" in Zamenhof's language. In 1887, Zamenhof wrote a description of this language and published it. He used a pen name, Dr. Esperanto, when signing the book. He selected the name Esperanto because this word means "a person who hopes" in his language. Esperanto clubs began popping up throughout Europe, and by 1950, Esperanto had spread from Europe to America and Asia. In 1905, the First World Congress of Esperanto took place in France, with approximately 700 attendees from 20 different countries. Congresses were held annually for nine years, and 4,000 attendees were registered for the Tenth World Esperanto Congress scheduled for 1914, when World War I erupted and forced its cancellation. Esperanto has had its ups and downs in the period since World War I. Today, years after it was introduced, it is estimated that perhaps a quarter of a million people are flent in it. This may seem like a large number, but it is really quite small when compared with the billion English speakers and billion Mandarin Chinese speakers in in today's world. Current advocates would like to see its use grow considerably and are taking  steps to try to make this happen.
3. It can be inferred from the passage that the Esperanto word "malespera" means..........

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

   As viewed from space, Earth’s distinguishing characteristics are its blue waters and white clouds. Enveloped by an ocean of air consisting of 78% nitrogen and 21% oxygen, the planet is the only one in our solar system known to harbor life. Circling the Sun at an average distance of 149 million kilometers (93 million miles), Earth is the third planet from the Sun and the fifth largest planet in the solar system.

   Our planet’s rapid spin and molten nickel-iron core give rise to an extensive magnetic field which, coupled the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Earth’s atmosphere protects us from meteors as well, most of which burn up in the Earth’s atmosphere before they can strike the surface. The planet active geological processes have left no evidence of the ancient pelting it almost certainly received soon after it formed about 4.6 billion years ago. The Earth has a single natural satellite – the moon.

What two factors help protect the Earth from radiation?

Read the following passage and choose the best answer (A, B, C, D):
Technology has become a fantastic and useful tool in the classroom. Teachers are  expected to make (1) _________________ if it to enhance the learning experience and information dissemination. However, knowledge of the different tools available, what they can do, and their impact allows teachers to use them (2) _____________. With numerous technology users actively involved in developing gadgets of the future, we can only specular what new advances will be making their way (3) _______________ classrooms in the coming days.  Following the evolution of technology, educational capabilities are changing and growing daily. The internet is a vast library of data that is useful in (4) _________________ the landscape of education as we know it. All in all, technology alone will not change education. Good grades and practical knowledge are as important as ever. Technology in education is therefore simply a catalyst, a tool for conveying lessons (5) _______________ effectiveness cannot be overlooked

Read the following passage and choose the best answer (A, B, C, D):
Generation gap refers to a vast difference in cultural norms between a younger generation and their elders. It’s a distressing thing for the phenomenon (1) ____ occurs around the world. The (2) ____ of communication, different views on certain problems and different attitudes towards life may cause the generation gap or even widen it. First, one of the major factors for this misunderstanding between two generations is that parents and children lack communication. Young people (3) ____ reveal their feelings to their parents, and often complain that their parents are out of (4) ____ with modern days, that they are dominant, that they do not trust their children to deal with crises, and that they talk too much about certain problems. So when young people meet some problems, they would rather (5) ____ to their classmates or their friends for help. The lack of communication widens the generation gap Another factor is that parents and their children see almost everything from different (6) ____. Take choosing career as an example. Parents generally believe it is their responsibility to plan the career for their children. Some hope their children will (7) ____ professions that will bring them greatest prestige and economic benefits. Some hope children will have a stable job with a regular income. But the youth may think they should be free to (8) ____ their own decisions as to their future career. Young people explain that true success is not a matter of money or position, instead, it is a matter of self-fulfillment. Finally, with the change of the world over decades, the attitude of the young has altered too. There are differences in (9) ____ matters as musical tastes, fashions, drug use, sex and politics between the young people and their elders. Nowadays long hair on young males is viewed as fashion by the young, but it is frequently considered a shocking act of rebellion against (10) ____ norms by parents

Read the following passage and choose the best answer (A, B, C, D):
Children can learn a lot from doing household chores. Doing chores helps children learn about (1)___________ they need to do to care for themselves, a home and a family. They learn skills they can use in their adult lives, like preparing meals, cleaning, organizing and keeping a garden. (2)________in chores also gives children experience of relationship skills like communicating clearly, negotiating, cooperating and working as a team. When children (3)_________ to family life, it helps them feel competent and responsible. Even if they don’t enjoy the chore, when they keep going they get the feeling of satisfaction that comes with finishing a task. And sharing housework can also help families work better and reduce family stress. When children help out, chores get done sooner, and parents have less to do. This frees up time for the family to spend doing fun things together. The secret for involving children in household chores is asking for contributions that you (4)__________ and that suit your children’s ages and abilities. A chore that’s too hard for a child can be frustrating – or even dangerous – and one that’s too easy might be boring. Even a young child can start to help out if you choose activities that are right for his age. You can start with simple jobs like looking after his own toys. Chores like this send the message to your child that his contribution is important. If your child is old enough, you can have a family discussion (5)___________ chores. This can reinforce the idea that the whole family contributes to how the household runs

Find synonym:
The urban planners are working for Eco Infrastructure Network, whose main function is to deal with urban environmental problems to make Super Star City greener, cleaner, and more sustainable.

Of the six outer planets, Mars, commonly called the red planet, is the closest to Earth. Mars, 4,200 miles in diameter and 55 percent of the size of Earth, is 34,600,000 miles from Earth, and 141,000,000 miles from the Sun. It takes this planet, along with its two moons, Phobos and Deimos, 1.88 years to circle the Sun, compared to 365 days for the Earth.

For many years, Mars had been thought of as the planet with the man-made canals, supposedly discovered by an Italian astronomer, Schiaparelli, in 1877. With the United States spacecraft Viking I's landing on Mars in 1976, the man-made canal theory was proven to be only a myth.

Viking I, after landing on the soil of Mars, performed many scientific experiments and took numerous pictures. The pictures showed that the red color of the planet is due to the reddish, rocky Martian soil. No biological life was found, though it had been speculated by many scientists. The Viking also monitored many weather changes including violent dust storms. Some water vapor, polar ice, and permafrost (frost below the surface) were found, indicating that at one time there were significant quantities of water on this distant planet. Evidence collected by the spacecraft shows some present volcanic action, though the volcanoes are believed to be dormant, if not extinct.

All of the following are true EXCEPT ___________.

Mark the letter A, B, C, or D on your answer sheet to indicate the undelined part that needs correction in each of the following questions:
There are three valid arguments to support the preservation of endangered species. An aesthetic justification contends that biodiversity contributes to the quality of life because many of the endangered plants and animals are particularly appreciated for their unique physical beauty. The aesthetic role of nature in all its diverse forms is reflected in the art and literature of every culture, attaining symbolic status in the spiritual life of many groups. According to the proponents of the aesthetic argument, people need nature in all its diverse and beautiful forms as part of the experience of the world.
Another argument that has been put forward, especially by groups in the medical and pharmacological fields, is that of ecological self-interest. By preserving all species, we retain a balance of nature that is ultimately beneficial to humankind. Recent research on global ecosystems has been cited as evidence that every species contributes important or even essential functions that may be necessary to the survival of our own species. Some advocates of the ecological argument contend that important chemical compounds derived from rare plants may contain the key to a cure for one of the diseases currently threatening human beings. If we do not protect other species, then they cannot protect us.
Apart from human advantage in both the aesthetic and ecological arguments, the proponents of a moral justification contend that all species have the right to exist, a viewpoint stated in the United Nations World Charter for nature, created in 1982. Furthermore, if humankind views itself as the stewards of all the creatures on Earth, then it is incumbent upon human beings to protect them, and to ensure the continued existence of all species. Moral justification has been extended by a movement called “deep ecology,” the members of which rank the biosphere higher than people because the continuation of life depends on this larger perspective. To carry their argument to its logical conclusion, all choices must be made for the biosphere, not for people.

The author mentions all of the following as justifications for the protection of endangered species EXCEPT    .

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions:
We have all had bad experiences with restaurants, stores, or hotels. Maybe you have gone to a restaurant that served terrible food. Perhaps you have gone to a store that had high prices or bad service. Or maybe you have booked a hotel and found out later that the room was nothing like the advertisement.
These days, we have a better chance of preventing these unpleasant surprises. We can do this by using apps. “App” is short for “application”. An app is a computer programme on a smartphone. You can use apps to do almost anything. Apps can help you play games, get directions, talk to friends, and so on.
If f you want to find information about a store or a hotel, you can use a review app. Review apps help us evaluate services and products before we hand over our money. The idea is very simple. After you go to a restaurant or stay in a hotel, you can post a review with one of your apps. You can say anything you want. If you like a hotel you stayed in, you can tell people that it was wonderful. If you think that the food in a certain restaurant was bad, then you tell people not to eat there. Other people can use their apps to read your reviews.
Plenty of people prefer not to use these review apps. Many of these people prefer to go out and decide for themselves whether or not a service is good. However, review apps are getting more and more popular every day. Some apps are for specific services. For example, Tripadvisor focuses on travel, and Goodreads focuses on books. There are also other, larger apps that provide information for just about every service that you can think of. 5

Which of the following would be another good title for the passage?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions:
In 1972. a century after the first national park in the United States was established at Yellowstone, legislation was passed to create the National Marine Sanctuaries Program. The intent of this legislation was to provide protection to selected coastal habitats similar to that existing for land areas designated as national parks. The designation of an areas a marine sanctuary indicates that it is a protected area, just as a national park is. People are permitted to visit and observe there, but living organisms and their environments may not be harmed or removed.
The National Marine Sanctuaries Program is administered by the National Oceanic and  Atmospheric Administration, a branch of the United States Department of Commerce. Initially, 70 sites were proposed as candidates for sanctuary status. Two and a half decades later, only fifteen sanctuaries had been designated, with half of these established after 1978. They range in size from the very small (less than 1 square kilometer) Fagatele Bay National Marine Sanctuary in American Samoa to the Monterey Bay National Marine Sanctuary in California, extending over 15,744 square kilometers.
The National Marine Sanctuaries Program is a crucial part of new management practices in which whole communities of species, and not just individual species, are offered some degree of protection from habitat degradation and overexploitation. Only in this way can a reasonable degree of marine species diversity be maintained in a setting that also maintains the natural interrelationships that exist among these species.
Several other types of marine protected areas exist in the United States and other countries. The National Estuarine Research Reserve System managed by the United States government, includes 23 designated and protected estuaries. Outside the United States, marine protected-area programs exist as marine parks, reserves and preserves.
Over 100 designated areas exist around the periphery of the Caribbean Sea. Others range from the well-known Australian Great Barrer Reef Marine Park to lesser-known parks in countries such as Thailand and Indonesia, where tourism is placing growing pressures on fragile coral reef systems. As state, national, and international agencies come to recognize the importance of conserving marine biodiversity, marine projected areas whether as sanctuaries,parks, or estuarine reserves, will play an increasingly important role in preserving that diversity.

The word “periphery” in the passage is closest in meaning to

Read the following passage and choose the best answer (A, B, C, D):
Though overwhelmed by the news of the novel coronavirus outbreak, Munyaradzi Gurure, the 21-year-old student at Guangxi University of Finance and Economics from South Africa, has still stepped out to serve as a volunteer in the train station to help battle the epidemic.  “I’m well aware the situation of epidemic prevention and control is very severe,” he said. “Seeing that many people actively joined in the fight, I also wanted to do my part and volunteer at the station.” With the number of novel coronavirus cases continuing to rise both in and outside of China, Gurure’s family back in South Africa was very worried about his health, and hoped he would quit the volunteer job. “I told my parents China has taken a lot of strong quarantine measures and is actually safe,” he said. “I want to do whatever I can to prevent the spread of the infection. The country took really good care of me during the last three years.”  Working about four hours a day, Gurure either carries an 8-kilogram electric sprayer to disinfect the waiting room or checks passengers’ temperature as soon as they walk into the station. He also makes sure people are in good health and wearing masks at all times. Though it’s not easy work, Gurure came across many Chinese who are very surprised to see a foreign face, but then give a thumbs up and say “very good” to him in Chinese. Gurure’s foreign classmates found out about his volunteer job and sent messages saying “good job”, some showing interest in joining him to help curb the spread of the virus. 
There are many ways in which you can help people with disabilities; however, be  aware that there are also ways you can hinder rather than help them. Please read through these tips before you try helping someone with a disability. Here are some general rules for helping all people with disabilities.  Always treat people with disabilities as equals. All people want to have friends, fun, and experience life to the maximum. People with disabilities are no exception. Never be afraid, skeptical, or embarrassed to approach someone with a disability. People with disabilities have just as much fun!  Always ask before you help. People with disabilities have varying levels of independence. Never assume someone with a disability has a low-level. If someone looks like they’re struggling, ask before you help. A person may welcome help, or they may ask that you let her be independent; but even if she looks like she’s struggling, she may just want to become more independent, which requires practice in everyday situations.  Never assume someone does or does not have a disability. Everyone is different. Sometime, people with disabilities may act, feel, or think differently than you. Don’t assume that for this reason someone has a disability, simply treat him/her as an individual because all people should be treated equally.  Do not stare. Sometimes it is an eye-opening experience to see someone with a disability in public. However, people with disabilities have lives just like everyone else. You are certainly allowed to look, but do not stare at a person with a disability. Simply view them the way you view others.  Respect and understand confidentiality. People with disabilities have a right to privacy. They are not obligated to tell you about their disability. If someone does tell you about his/her disability, do not assume that he/she is comfortable with you telling other people about his/her disability. Always ask permission to discuss the disability before you do it. 
1. What is it like to make friends with disabled people? 

Read the following passage and choose the best answer (A, B, C, D):
For nearly all of human history, there haven’t been that many of us. Around the year zero, Earth’s population is estimated to have been 190 million. A thousand years later, it was probably around 250 million. Then the Industrial Revolution happened, and human population went into overdrive. It took hundreds of thousands of years for humans to hit the 1 billion mark, in 1800. We added the next billion by 1928. In 1960, we hit 3 billion. In 1975, 4 billion. That sounds like the route to an overpopulation apocalypse, right? To many midcentury demographers, futurists, and science fiction writers, it certainly predicted one. Extending the timeline, they saw a nightmarish future ahead for humanity: human civilizations constantly on the brink of starvation, desperately crowded under horrendous conditions, draconian population control laws imposed worldwide. Stanford biologist Paul Ehrlich wrote in his best-selling book, “In the 1970’s, hundreds of millions of people will starve to death” because of overpopulation. None of that ever came to pass. The world we live in now, despite approaching a population of nearly 8 billion, looks almost nothing like the one doomsayers were anticipating. Starting in the 19th century in Britain and reaching most of the world by the end of the 20th century, birthrates plummeted — mostly because of women’s education and access to contraception, not draconian population laws. In wealthy societies where women have opportunities outside the home, the average family size is small; in fact, it’s below replacement level. Called the demographic transition, it is one of the most important phenomena for understanding trends in global development.  There’s still significant debate among population researchers about the extent of the sea change in population trends. Researchers disagree on whether global populations are currently on track to start declining by midcentury. There’s also disagreement on what the ideal global population figure would be, or whether it’s morally acceptable to aim for such a figure. While academic research seeks to nail down these questions, it’s important to be clear what is consensus among researchers. Our projections around population are used to make global health and development policy. They’re critical for planning, especially about climate change. Fears of overpopulation sometimes turn into hostility to immigrants, those who choose to have large families, and countries in an earlier stage of their population transition. Having an informed conversation about population is crucial if we are to get humanity’s future right.  
6. According to paragraph 3, what is the reason for dwindling replacement rate?

Read the following passage and choose the best answer (A, B, C, D):
How fit are your teeth? Are you lazy about brushing them? Never fear: An inventor is on the case. An electric toothbrush senses how long and how well you brush, and it lets you track your performance on your phone. The Kolibree toothbrush was exhibited at the International Consumer Electronics Show in Las Vegas this week. It senses how it is moved and can send the information to an Android phone or iPhone via a Bluetooth wireless connection The toothbrush will be able to teach you to brush right (don’t forget the insides of the teeth!) and make sure you’re brushing long enough. “It’s kind of … like having a dentist actually watch your brushing on a day-to-day basis,” says Thomas Serval, the French inventor. The toothbrush will also be able to talk to other applications on your phone, so developers could, for instance, create a game controlled by your toothbrush. You could score points for beating monsters among your teeth. “We try to make it smart but also fun.” Serval says he was inspired by his experience as a father. He would come home from work and ask his kids if they had brushed their teeth. They said “yes,” but Serval would find their toothbrush heads dry. He decided he needed a brush that really told him how well his children brushed. The company says the Kolibree will go on sale this summer, for $99 to $199, developing on features. The U.S. is the first target market. Serval says that one day, it’ll be possible to replace the brush on the handle with a brushing unit that also has a camera. The camera can even examine holes in your teeth while you brush.
5. What can we learn about the future development of the Kolibree?

Find mistake:
They used to eating potatoes when they were in the village but now they don’t.