The ability to conduct electricity is one of the key properties of a metal. Other solid material such as silicon can conduct electricity but only effectively at certain temperatures. Also, some substances such as salt (sodium chloride) can conduct when molten or when dissolved in water. The ability of metals to conduct electricity is due to how their atoms bond together. In order to bond together the metal atoms lose at least one of their outermost electrons. This leaves the metal atoms with a positive charge and they are now strictly ions. The lost electrons are free to move in what are known as a sea of electrons. Since the electrons are negatively charged they attract the ions and this is what keeps the structure together.

An electric current is a flow of charge and since the electrons in the sea of electrons are free to move they can be made to flow in one direction when a source of electrical energy such as a battery is connected to the metal. Hence we have an electric current flowing through the wire, and this is what makes metals such good conductors of electricity. The only other common solid conducting material that pencil users are likely to encounter is graphite (what the 'lead' of a pencil is made from). Graphite is a form of carbon and again the carbon atoms bond in such a way that there is a sea of electrons that can be made to flow as an electric current. Likewise, if we have an ionic substance like salt we can make the electrically charged ions flow to create a current but only when those ions are free to move, either when the substance is a liquid or dissolved in water. In its solid state an ionic substance like salt cannot conduct electricity as its charged ions cannot flow.

Electrical insulators are substances that cannot conduct electricity well either, because they contain no charged particles or any charged particles they might contain do not flow easily. Water itself is a poor conductor or electricity as it does not contain a significant amount of fully charged particles (the ends of a water molecule are partly charged but overall the molecule is neutral). However, most water we encounter does contain dissolved charged particles, so it will be more conductive than pure water. Many of the problems that occur when touching electrical devices with wet hands result from the ever-present salt that is left on our skin through perspiration and it dissolves in the water to make it more conductive.

The atoms of a metal can bond together because________.

Choose the best answer:
After working hard for hours, the farmers sat down and ___________ a short rest.

Choose the best answer:
It was an_________ day.

Most doctors and nurses have to work on a ____ once or twice a week at the hospital.

(188)_______

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:
Overpopulation, the situation of having large numbers of people with too few resources and too little space, is closely associated with poverty. It can result from high population density, or from low amounts of resources, or from both. Excessively high population densities put stress on available resources. Only a certain number of people can be supported on a given area of land, and that number depends on how much food and other resources the land can provide. In countries where people live primarily by means of simple farming, gardening, herding, hunting, and gathering, even large areas of land can support only small numbers of people because these labor-intensive subsistence activities produce only small amounts of food.
In developed countries such as the United States, Japan, and the countries of Western Europe, overpopulation generally is not considered a major caus of poverty. These countries produce large quantities of food through mechanized farming, which depends on commercial fertilizers, large-scale irrigation, and agricultural machinery. This form of production provides enough food to support the high densities of people in metropolitan areas.
A country’s level of poverty can depend greatly on its mix of population density and agricultural productivity. Bangladesh, for example, has one of the world’s highest population densities, with 1, 147 persons per sq km. A large majority of the people of Bangladesh engage in low – productivity manual farming, which contributes to the country’s extremely high level of poverty. Some of the smalleer countries in Western Europe, such as the Netherlands and Belgium, have high population densities as well. These countries practice mechanized farming and are involved in high-tech industries, however, and there fore have high standards of living.
At the other end of the spectrum, many countries in sub-Saharan Africa have population densities of less than 30 persons per sq km. Many people in these countries practice manual subsistence farming; these countries also have infertile land, and lack the economic resources and technology to boost productivity. As a consequence, these nations are very poor. The United States has both relatively low population density and high agricultural productivity; it is one of the world’s wealthiest nations.
High birth rates contribute to overpopulation in many developing countries. Children are assets to many poor families because they provide labor, usually for farming. Cultural norms in traditionally rural societies commonly sanction the value of large families. Also, the governments of developing countries often provide little or no support, financial or political, for family planning; even people who wish to keep their families small have difficulty doing so. For all these reasons, developing countries tend to have high rates of population growth.
(From “Poverty” by Thomas J. Corbett)

Which of the following is given a definition in paragraoh 1?

Read the following passage and choose the best answer (A, B, C, D):
It is often the case with folktales that they develop from actual happenings but in their development lose much of their factual base; the story of Pocahontas quite possibly fits into this category of folktale. This princess of the Powhatan tribe was firmly established in the lore of early America and has been made even more famous by the Disney film based on the folktale that arose from her life. She was a real- life person, but the actual story of her life most probably differed considerably from the folktale and the movie based on the folktale. Powhatan, the chief of a confederacy of tribes in Virginia, had several daughters, none of whom was actually named Pocahontas. The nickname means "playful one" and several of Powhatan's daughters were called Pocahontas. The daughter of Powhatan who became the subject of the folktale was named Matoaka. What has been verified about Matoaka, or Pocahontas as she has come to be known, is that she did marry an Englishman and that she did spend time in England before she died there at a young age. In the spring of 1613, a young Pocahontas was captured by the English and taken to Jamestown. There she was treated with courtesy as the daughter of chief Powhatan, While Pocahontas, was at Jamestown, English gentleman John Rolfe fell in love with her and asked her to marry. Both the governor of the Jamestown colony and Pocahontas's father Powhatan approved the marriage as a means of securing peace between Powhatan's tribe and the English at Jamestown. In 1616, Pocahontas accompanied her new husband to England, where she was royally received. Shortly before her planned return to Virginia in 1617, she contracted an illness and died rather suddenly. A major part of the folktale of Pocahontas that is unverifiedconcerns her love for English Captain John Smith in the period of time before her capture by the British and her rescue of him from almost certain death. Captain John Smith was indeed at the colony of Jamestown and was acquainted with Powhatan and his daughters; he even described meeting them in a 1612 journal. However, the story of his rescue by the young maiden did not appear in his writings until 1624, well after Pocahontas had aroused widespread interest in England by her marriage to an English gentleman and her visit to England. It is this discrepancy in dates that has caused some historians to doubt the veracity of the tale. However, other historians do argue quite persuasively that this incident did truly take place.
5. It can be inferred from the passage that Pocahontas........

The Doi Moi reforms have ______ new possibilities in farming systems research in Vietnam.

(292)______

Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks.

Rapid urbanization can hold long-term economic, social and environmental promise for developing countries (23) ____ investments made now in infrastructure, housing and public services are efficient and sustainable, the World Bank says in a new report.

In the next two decades, cities are (24) ____ to expand by another two billion residents, as people move in unprecedented numbers from rural areas to pursue hopes and aspirations in cities. More than 90% of this urban population growth is expected to occur in the developing world, (25) ____ many cities are already struggling to provide basic needs such as water, electricity, transport, health services and education.

Report authors note that most new urban growth will not take (26) ____ in the “megacities” of the world e.g. Rio de Janeiro, Jakarta or New Delhi but rather in less commonly recognized “secondary” cities - places like Fushun in China, and Surat in India.

To help policymakers prepare for and manage growth, the report distills lessons learned from 12 countries across all geographic regions and stages of urbanization. It then translates these global lessons (27) ____ practical policy advice.

25................

Choose the best answer:
There are 54 ………. minorities in Vietnam.

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:
The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, eg., rural or urban; the type of restaurant, eg., informal or formal; and certain standards that are more universal. In other words, some standards of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurant determine etiquette appropriate to them, some rules apply to all restaurant.

With what topic is this passage primarily concerned?

Choose the best answer:
The US first __________ of the Moon began with the Ranger 4 impactor in 1962.

My family consists of four people. There’s my father whose name is Jan, my mother whose name is Marie, my brother Peter and of course me. I have quite a large extended family as well but only the four of us live together in our apartment in a block of flats. My father is fifty-two years old, he works as an accountant in an insurance company. He is tall and slim, has got short brown and grey hair and blue eyes. My father likes gardening very much as well as listening to music and reading books about political science. His special hobbies are bird watching and travelling.

Now I’ll describe my mother and my brother. My mother is forty-seven and she works as a nurse in a hospital. She is small and slim, has got short brown hair and green eyes. She likes bird watching and travelling too, so whenever my parents are able to them go to some places interesting for nature watching. Since we have a cottage with a garden they both spend a lot of time there. My brother is sixteen. He is slim and has short brown hair and blue eyes. He also attends high school. He is interested in computers and sports like football and hockey. He also spends a lot of time with his friends.

I have only one grandmother left still living. She is in pretty good health even at the age of seventy- eight so she still lives in her own flat. I enjoy spending time with her when I can. Both my grandfathers died from cancer because they are smokers, which was really a great tragedy because I didn’t get a chance to know them. My other grandmother died just a few years ago. I also have a lot of aunts, uncles, and cousines. The cousine I’m closest to is my uncle’s daughter Pauline. We have a lot in common because we are both eighteen and so we are good friends.

My parents have assigned me certain duties around the house. I don’t mind helping out because everyone in a family should contribute in some way. I help with the washing up, the vacuuming and the shopping. Of course, I also have to help keep my room tidy as well. My brother is responsible for the dusting and the mopping. He also has to clean his own room. Even though my brother and I sometimes fight about who has to do what job, we are still very close. I am also very close to my parents and I can rely on them to help me. My parents work together to keep our home well maintained and it seems they always have some projects or another that they are working on. They respect each other’s opinions and even if they disagree they can always come to a compromise. I hope in the future that I have a family like ours.

What does the writer’s mother look like?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the word(s) that best fits each of the numbered blanks .
Around 200 million people are employed in tourism worldwide, making it the largest industry in the modern global economy. It is estimated that three-quarters of a billion people go on holiday each year, and  industry  planners  expect  this  figure  to  double  (1)............... 2020. Some of the biggest beneficiaries are less developed countries, where it is often their main source of income.
(2)......... , along with the economic benefits, this mass movement of people has resulted in environment. People often forget the damage caused by carbon emissions from aircraft, (3)............  contribute directly to global warming. Deforestation has cleared land in order to build hotels, airports and roads, and this has destroyed wildlife. In some areas, water shortages are now common because of the need to fill swimming pools and water golf courses for tourists. By pushing up prices for goods and services, tourism can also be harmful to people living in tourist destinations.
In  response  to  these  (4)....................... , some travel operators now offer  environment-friendly holidays. Many of these aim to reduce the negative effects of tourism  by (5)............only hotels that have invested equipment to recycle waste and use energy and water efficiently. Increasingly, tourists are also being reminded to show respect for customs of the people whose countries they are going to visit, and to support local businesses, such as restaurants and shops which depend on tourism for their main income.
(2)..............................

Choose the best answer:
I ………. Da Lat three years ago.

Choose the answer that is nearest in meaning to the sentence printed before:
 Marry loved her stuffed animal when she was young. She couldn’t sleep without it.

Read the following passage and choose the best answer (A, B, C, D):
According to Vietnamese legend, (1) ____ giant turtle in Hanoi's Hoan Kiem Lake reclaimed a magic sword given to King Le Loi in the 15th century that he used to win independence (2) ____ China's Ming Dynasty. The lake was thereafter named 'Ho Hoan Kiem', or 'Lake of the Returned Sword', and Hanoi has been built up (3) ____ it. Margie Mason of Associated Press wrote: "(4) ____ once was a magic golden turtle that lived in Hanoi's most enchanted lake. The giant turtle was believed so powerful, it snatched a divine sword from a warrior king and returned it to the gods of the depths nearly six centuries (5) ____. That tale has long been a (6) ____ among young and old Vietnamese living in the capital city, but folklorists soon may have to rewrite the story to (7) ____ a very sad ending. In real life, the last giant soft-shell turtle (8) ____ in Hoan Kiem Lake probably will die alone, and at least one biologist says the species (9) ____ then be extinct. The elusive creature - with a shell as big as a desk - occasionally pokes its wrinkled head out of the murky waters of the downtown lake to (10) ____ a breath, but few Vietnamese are lucky enough to glimpse it. And certainly no one knows its age."

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:
In ancient times, some of the first celebrities were Roman gladiators. Rather like today’s TV talent-show contestants, these men fought each other for the audience’s entertainment. Fast forward to the 18th century, it was politicians and preachers who were able to become celebrities through public (1)__________. George Whitefield, for example, a preacher from England, (2)___________ a crowd of 30,000 when he visited the US city of Boston. It’s no wonder he was called ‘Anglo-America’s first modern celebrity’. In the 19th century, the arrival of cheap newspapers created a sudden (3)___________ for exciting stories. All kinds of people began to get their 15 minutes of fame, including the legendary American outlaw and bank robber, Jesse James, and one of the world’s first media celebrities, Sam Patch. Patch became famous for jumping into rivers from high places, and he became a (4)___________ name by leaping into Niagara Falls. He survived every jump, except the last one into the Genesee River in New York. In the same way that the media is held (5)___________ for celebrity problems today, people blamed the pressure of the media for Patch’s sudden end

Read the reading below carefully, and then complete it with the best option A, B, C or D given below:
Birthday is the day when a person was (1) _______. In many places, on a person's birthday, he or she celebrates with friends and family at a party, where they eat cake or other food, and get gifts. Many religions celebrate the birth of their founders or religious figures with special holidays. In each country, (2) _______ there is a different version of the song call “Happy Birthday”, they still share the same meaning as well as rhythm. In many legal systems, the age of that newborn is 0 years old. But in Korea, they are already one years old. This creates confusion to many people who work with Koreans because they can’t (3) _______ the rules of calculating age. A person could be 16 in the US but 18 (4) _______ he or she is Korean, despite being born in the same year. This is why Koreans usually tell their age by saying the year they were born in instead of (5) _______ telling their age

Choose the best answer:
How much is a washing machine?

Choose the best answer:
I bought this new software _____ Chinese.

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:
There are three valid arguments to support the preservation of endangered species. 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.

Where in the passage does the author explain how rare species contribute to the health of the human species?