Without the traffic jam on the high way this morning, I _________late for the meeting.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the blanks.
        Here are the tips that help success in your job interview
Always  arrive  early.  If  you  do  not  know   (1)......   the  organization  is  located,  call  for  exact  directions in advance. Leave some extra time for any traffic, parking, or unexpected events. If you are running late, call right away and let someone know. The best time to arrive is approximately 5 - 10 minutes early. Give yourself the time to read your resume one more time, to catch your breath, and to be ready for the interview. Once you are at the office, treat everyone you encounter with respect. Be (2).....  to everyone as soon as you walk in the door. Wear a professional business suit. This point  should be emphasized enough. First (3)...........are extremely important in the interview process.  Women should not wearing too much jewelry or make up. Men should  (4)....... flashy suits or wearing too much perfume. It is also important that you feel comfortable. While a suit is the standard interview attire in a business environment, if you think it is an informal environment, call before and ask. (5)........ , you can never be overdressed if you are wearing a tailored suit.
(2)........................................

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:
Scientists do not yet thoroughly understand just how the body of an individual becomes sensitive to  a substance that is harmless or even wholesome for the average person. Milk, wheat, and egg, for example, rank among the most healthful and widely used foods. Yet these foods can cause persons sensitive to them to suffer greatly. At first, the body of the individual is not harmed by coming into
contact with the substance. After a varying interval of time, usually longer than a few weeks, the body becomes sensitive to it, and an allergy has begun to develop. Sometimes it's hard to figure out if you have a food allergy, since it can show up so many different ways.
Your symptoms could be caused by many other problems. You may have rashes, hives, joint pains mimicking arthritis, headaches, irritability, or depression. The most common food allergies are to milk, eggs, seafood, wheat, nuts, seeds, chocolate, oranges, and tomatoes. Many of these allergies will not develop if these foods are not fed to an infant until her or his intestines mature at around seven months. Breast milk also tends to be protective. Migraines can be set off by foods containing tyramine, phenathylamine, monosodium glutamate, or sodium nitrate. Common foods which contain these are chocolate, aged cheeses, sour cream, red wine, pickled herring, chicken livers, avocados, ripe bananas, cured meats, many Oriental and prepared foods (read the labels!).
Some people have been successful in treating their migraines with supplements of B-vitamins, particularly B6 and niacin. Children who are hyperactive may benefit from eliminating food additives, especially colorings, and foods high in salicylates from their diets. A few of these are almonds, green peppers, peaches, tea, grapes. This is the diet made popular by Benjamin Feingold, who has written the book “Why your Child is Hyperactive”. Other researchers have had mixed results.

The author states that the reason that infants need to avoid certain foods related to allergies has to do with the infant's     .

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:
No sooner had the first intrepid male aviators safely returned to Earth than it seemed that women, too, had been smitten by an urge to fly. From mere spectators, they became willing passengers and finally pilots in their own right, plotting their skills and daring line against the hazards of the air and the skepticism of their male counterparts. In doing so they enlarged the traditional bounds of a women's world, won for their sex a new sense of competence and achievement, and contributed handsomely to the progress of aviation.
But recognition of their abilities did not come easily. "Men do not believe us capable." The famed aviator Amelia Earhart once remarked to a friend. "Because we are women, seldom are we trusted to do an efficient job." Indeed old attitudes died hard: when Charles Lindbergh visited the Soviet Union in 1938 with his wife, Anne–herself a pilot and gifted proponent of aviation – he was astonished to discover both men and women flying in the Soviet Air Force.
Such conventional wisdom made it difficult for women to raise money for the up – to – date equipment they needed to compete on an equal basis with men. Yet they did compete, and often they triumphed finally despite the odds.
Ruth Law, whose 590 – mile flight from Chicago to Hornell, New York, set a new nonstop distance record in 1916, exemplified the resourcefulness and grit demanded of any woman who wanted to fly. And when she addressed the Aero Club of America after completing her historic journey, her plainspoken wordstestified to a universal human motivation that was unaffected by gender: "My flight was done with no expectation of reward," she declared, "just purely for the love of accomplishment."

What can be inferred from the passage about the United States Air Force in 1938?

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.
       Early writing and Alphabets
When people first began to write, they did not use an alphabet. Instead, they drew small pictures to (1)........  the objects they were writing about. This was very slow because there was a different picture for every word.
The  Ancient  Egyptians  had a (2).......... of picture writing that was called hieroglyphics. The meaning of this writing was forgotten for a very long time but in 1799 some scientists (3)............ a stone near Alexandria, in Egypt. The stone had been there for over a thousand years. It had both Greek and hieroglyphics on it and researchers were finally able to understand what the hieroglyphics meant.
An alphabet is quite different from picture writing. It (4)............ of letters or symbols that represent a sound and each sound is just  part  of  one  word.  The  Phoenicians,  who  lived  about  3,000 years ago, developed the modern alphabets. It was later improved by the Roman's and this alphabet is now used (5)........... throughout the world.
(3)...........................

They ________ what the manager said, and didn't know what to do.

Read the passage carefully and choose the correct answer.

University Entrance Examination is very important in Vietnamese students. High school graduates have to take it and get high results to be admitted to universities. The pressure on the candidates remains very high despite the measures that have been taken to reduce the heat around these exams, since securing a place in a state university is considered a major step towards a successful career for young people, especially those from rural areas or disadvantaged families. In the year 2004, it was estimated that nearly 1 million Vietnamese students took the University Entrance Examination, but on average only 1 out of 5 candidates succeeded.  Normally, candidates take 3 exam subjects, and each lasts; 180 minutes for the fixed group of subjects they choose. There are 4 fixed groups of subjects: Group A: Mathematics, Physics, and Chemistry; Group B: Mathematics, Biology, and Chemistry; Group C: Literature, History, and Geography; Group D: Literature, Foreign Language, and Mathematics.

In addition to universities, there are community colleges, art and technology institutes; professional secondary schools, and vocational schools which offer degrees or certificates from a-few-month to 2-year courses. According to Vietnam's Ministry of Education and Training, there are currently 23 non-public universities, accounting for 11% of the total number of universities. These non-public universities are currently training 119,464 students, or 11.7% of the total number of students. The government is planning to increase the number of non-public universities to 30% by 2007.

Which sentence refers to the University Entrance Examination in Vietnam?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks. 
Acupuncture is a Chinese method of treating illnesses by inserting needles into certain points of the body. The idea is that this restores the natural balance of energy, (23) ________ is disturbed when a person is ill. The origins of this therapy have been traced back over five thousand years, but it only began to be accepted in the West in the 1970s. 
In 1971, James Reston, a well-known journalist from the New York Times, was visiting China when he developed appendicitis. He was operated (24) _____________ in a hospital in Peking, where the doctors used acupuncture to relieve his pain. Reston was surprised at how (25) _____________ it was, and wrote about it in an article for the newspaper. 
Soon afterwards, Chairman Mao Tse-tung invited a group of distinguished Western doctors over to China to witness for themselves that (26) ________ worked. They were accompanied by television crews, and soon viewers in the West were watching operations being carried out on patients with acupuncture needles sticking out of them. The patients felt no pain. 
The Western experts were a little embarrassed at what they saw, because they had (27) _____________ ridiculed the idea that patients could be treated with needles. But now they were forced to admit that it actually worked, and acupuncture became a popular form of therapy. 

(23)........................

Fiberscopes are one of the most important Outcomes of the science of fiber optics. Fibers made of glass and transparent acrylic plastic are capable of conveying light energy, and when thousands of these fibers are combined in what is called a fiberscope, they can transmit images. The most common fiberscopes contain about 750,000 fibers, each 0.001 centimeter, or 10 microns, in diameter. For certain uses, the diameter of the fiber may be as small as 5 microns.
Fiberscopes have a wide range of applications. In the medical field, physicians use fiberscopes to examine internal organs and as an aid in delicate surgeries. Miniature probes have also been developed to view muscle fiber, skin tissue, and blood cells. Fiberscopes have also found varied uses in industry, particularly to inspect or control operations in inaccessible areas. Bundles of fiberscopes fused together in a solid plate, called a faceplate, are being used in the manufacture of television picture tubes and other cathode-ray tube devices. 
The most far-reaching applications of fiber-optic technology are in communications. Optical fibers carry voice messages for telephone service. The sound of the voice is electronically broken down into thousands of pulses per second, which causes a transmitting laser to send coordinated pulses of light through the optical fibers. At the receiving end, the light pulses are converted to electrical signals and the voice message is reconstructed. Light-wave communication systems can handle an immensely greater number of telephone calls and television programs than the current system, and they will form the basis of the "electronic superhighway" expected to crisscross the nation in the near future of the information age.

How do optical fibers carry voice messages?

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:
Body language is a vital form of communication. In fact, it is believed that the various forms of body language contribute about 70 percent to our comprehension. It is important to note, however, that body languages varies in different cultures. Take for example, eye movement. In the USA a child is expected to look directly at a parent or teacher who is scolding him/her. In other cultures the opposite is true. Looking directly at a teacher or parent in such a situation is considered a sign of disrespect.
Another form of body language that is used differently, depending on the culture, is distance. In North America people don’t generally stand as close to each other as in South America. Two North Americans who don’t know each other well will keep a distance of four feet between them, whereas South Americans in the same situation will stand two to three feet apart. North Americans will stand closer than two feet apart only if they are having a confidential conversation or if there is intimacy between them.
Gestures are often used to communicate. We point a finger, raise an eyebrow, wave an arm – or move any other part of the body - to show what we want to say. However, this does not mean that people all over the world use the same gestures to express the same meanings. Very often we find that the same gestures can communicate different meanings, depending on the country. An example of a gesture that could be misinterpreted is sticking out the tongue. In many cultures it is a sign of making a mistake, but in some places it communicates ridicule.
The dangers of misunderstanding one another are great. Obviously, it is not enough to learn the language of another culture. You must also learn its non-verbal signals if you want to communicate successfully.

The word “misinterpreted” in paragraph 3 is closest in meaning to     .

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.
Atypical person needs about 1,800 calories per day to stay running. They keep your organs operating (1)..... and your brain running. They also keep your body warm. A person gains weight because he or she consumes more calories per day than necessary. The only way to lose fat is to reduce the number of calories that you consume per day. This is the basic principle (2)........going on a diet.
Unfortunately, diets don’t work for most people. They do lose weight but then go off the diet and put it back. Building a sensible diet and exercise plan is the key to maintaining a consistent weight. You need to figure out how many calories you need in a day and how many you actually (3)..... . The next step is to add exercise so that you can raise the number of calories you can consume per day.
Burning 250 or 500 calories per day can make a big (4)...... . You can ride an exercise bike while you are watching television or you can take the stairs instead of the elevator. Find an exercise partner. Exercises can be a lot easier if there is someone to talk to. It’s a good idea to wear firm fitting clothes if you are (5)..... . Tight clothing acts as a reminder of what you are trying to accomplish.
(2)..................................

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 modem comic strip started out as ammunition in a newspaper was between giants of the American press in the late nineteenth century. The first full-color comic strip appeared in January 1894 in the New York World, owned by Joseph Pulitzer. The first regular weekly full- color comic supplement, similar to today's Sunday funnies, appeared two years later, in William Randolph Hearst's rival New York paper, the Morning Journal.
Both were immensely popular, and publishers realized that supplementing the news with comic relief boosted the sale of papers. The Morning Journal started another feature in 1896, the "Yellow Kid," the first continuous comic character in the United States, whose creator, Richard Outcault, had been lured away from the World by the ambitious Hearst. The "Yellow Kid" was in many ways a pioneer. Its comic dialogue was the strictly urban farce that came to characterize later strips, and it introduced the speech balloon inside the strip, usually placed above the characters' heads.
The first strip to incorporate all the elements of later comics was Rudolph Dirks's "Katzenjammer Kids", based on Wilhelm Busch's Max and Moritz, a European satire of the nineteenth century. The "Kids" strip, first published in 1897, served as the prototype for future American strips. It contained not only speech balloons, but a continuous cast of characters, and was divided into small regular panels that did away with the larger panoramic scenes of the earliest comics.
Newspaper syndication played a major role in spreading the popularity of comic strips throughout the country. Though weekly colored comics came first, daily black-and-white strips were not far behind. They first appeared in the Chicago American in 1904. It was followed by many imitators, and by 1915 black-and-white comic strips had become a staple of daily newspaper; around the country.

Why does the author mention Joseph Pulitzer and William Randolph Hearst?

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:
No sooner had the first intrepid male aviators safely returned to Earth than it seemed that women, too, had been smitten by an urge to fly. From mere spectators, they became willing passengers and finally pilots in their own right, plotting their skills and daring line against the hazards of the air and the skepticism of their male counterparts. In doing so they enlarged the traditional bounds of a women's world, won for their sex a new sense of competence and achievement, and contributed handsomely to the progress of aviation.
But recognition of their abilities did not come easily. "Men do not believe us capable." The famed aviator Amelia Earhart once remarked to a friend. "Because we are women, seldom are we trusted to do an efficient job." Indeed old attitudes died hard: when Charles Lindbergh visited the Soviet Union in 1938 with his wife, Anne–herself a pilot and gifted proponent of aviation – he was astonished to discover both men and women flying in the Soviet Air Force.
Such conventional wisdom made it difficult for women to raise money for the up – to – date equipment they needed to compete on an equal basis with men. Yet they did compete, and often they triumphed finally despite the odds.
Ruth Law, whose 590 – mile flight from Chicago to Hornell, New York, set a new nonstop distance record in 1916, exemplified the resourcefulness and grit demanded of any woman who wanted to fly. And when she addressed the Aero Club of America after completing her historic journey, her plainspoken wordstestified to a universal human motivation that was unaffected by gender: "My flight was done with no expectation of reward," she declared, "just purely for the love of accomplishment."

The word ‘skepticism’ is closest in meaning to     .

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:
One of the factors contributing to the intense nature of twenty-first-century stress is our continual exposure to media – particularly to an overabundance of news. If you feel stressed out by the news, you are far from alone. Yet somehow many of us seem unable to prevent ourselves from tuning in to an extreme degree.
The further back we go in human history, the longer news took to travel from place to place, and the less news we had of distant people and lands altogether. The printing press obviously changed all that, as did every subsequent development in transportation and telecommunication.
When television came along, it proliferated like a poplulation of rabbits. In 1950, there were 100,000 television sets in North American homes; one year later there were more then a million. Today, it’s not unusual for a home to have three or more television sets, each with cable access to perhaps over a hundred channels. News is the subject of many of those channels, and on several of them it runs 24 hours a day.
What’s more, after the traumatic events of Sptember 11, 2001, live newcasts were paired with perennial text crawls across the bottom of the screen – so that viewers could stay abreast of every story all the time.
Needless to say, the news that is reported to us is not good news, but rather disturbing images and sound bytes alluding to diasater (natural and man-made), upheaval, crime, scandal, war, and the like. Compounding the proplem is that when actual breaking news is scarce, most broadcasts fill in with waistline, hairline, or very existence in the future. This variety of story tends to treat with equal alarm a potentially lethal flu outbreak and the bogus claims of a wrinkle cream that overpromises smooth skin.
Are humans meant to be able to process so much trauma – not to mention so much overblown anticipation of potetial trauma – at once? The human brain, remember, is programmed to slip into alarm mode when danger looms. Danger looms for someone, somewhere at every moment. Exposing ourslves to such input without respite and without perspective cannot be anything other than a source of chronic stress.

According to the passage, when there is not enough actual breaking news, broadcasts

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:
A letter of application is a sales letter in which you are both salesperson and product, for the purpose of an application is to attract an employer’s attention and persuade him or her to grant you an interview. To do this, the letter presents what you can offer the employer, rather than what you want from the job.
Like a resume, the letter of application is a sample of your work and an opportunity to demonstrate your skills and personality. If it is written with flair and understanding and prepared with prefessional care, it is likely to be very effective. While the resume must be factual, objective, and brief, the letter is your chance to interpret and expand. It should state explicitly how your background relates to the specific job, and it should emphasise your strongest and most relevant characteristics. The letter should demonstrate that you know both yourself and the company.
The letter of application must communicate your ambition and enthusiasm. Yet it must be modest. It should be neither aggressive nor compliant: neither pat yourself on the back nor ask for sympathy. It should never express dissatisfaction with the present or former job or employer. And you should avoid discussing your reasons for leaving your last job.
Finally, it is best that you not broach the subject on salary. Indeed, even if a job advertisement requires that you mention your salary requirements, it is advisable simply to call them “negotiable.” However, when you go on an interview, you should be prepared to mention a salary range. For this reason, you should investigate both your field and, if possible, the particular company. You don’t want to ask for less than you deserve or more than is reasonable.

What is the passage mainly about?

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:
A mansion is a very large home. McDonald's is the name of a fast food hamburger chain. What do you get when you put the two together? You get McMansion, the recently created name for a type of  large suburban, two storied home that originated in the United States. Many people love McMansions for their low price, abundant space and impressive styling, but the news is not all good. In fact, McMansions may now be a threatened species.
McMansion became very popular in the United States during the 1990s, and this popularity continued for almost 20 years. During those years the economy was relatively strong, and banks were willing to lend large sums of money to people who wanted to buy a home. The result was an increase in the average home size. In 1988, the average new American home was 170 square meters, but by 2008 this had risen to 244 square meters, a 44% increase.
To offset the greater costs of these large homes, land developers built many homes that all used a similar basic design and identical construction methods. Framing and interior fittings were constructed in factories, instead of on site, and the materials used were often of a lower quality. Finally, the sections of land used for each house were much smaller than before.
The result was suburban developments full of huge homes, often over 280 square meters in floor area, that all looked similar to each other. Their standardization and lowest possible-cost construction reminded people of McDonald's hamburgers, hence the term McMansion. For many people a McMansion was their dream home, but that dream is now rapidly turning sour.
There are two main problems with McMansions. One problem is that their huge size means that they cost a lot to heat or cool. Energy is becoming more expensive, so owners are faced with huge bills if they try to heat or cool their home. The other problem is that McMansion owners are often in a lot of debt. They borrowed a lot of money to pay for their impressive home, but during the 2000s, with struggling economy and high unemployment, they couldn't afford to repay their loan.
McMansion are still popular in some area, but no one is sure how long it will last. Will energy become even more expensive and force owners to downsize? Will the economy grow and banks become more willing to end again? Will the drop-in house prices allow larger, less affluent families to afford a McMansion? These questions are weighing heavily on the future of one of the most popular housing styles of the late 20th century.

Why does the writer ask questions in paragraph 6?

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 modern comic strip started out as ammunition in a newspapaer war between giants of the American press in the late nineteenth century. The first full-color comic strip appeared in January 1894 in
the New York World, owned by Joseph Pulitzer. The first regular weekly full-color comic supplement, similar to today’s Sunday funnies, appeared two years later, in William Randolph Hearst’ rival New York paper, the Morning Journal.
Both were immensely popular and publishers realized that supplementing the news with comic relief boosted the sale of papers. The Morning Journal started another feature in 1896, the “Yellow Kid”, the first continuous comic character in the United States, whose creator, Richard Outcault, had been lured away from the World by the ambitious Hearst. The “Yellow Kid” was in many ways a pioneer. Its comic dialogue was the strictly urban farce that came to characterize later strips, and it introduced the speech baloon inside the strip, usually placed above the characters’ heads.
The first strip to incorporate all the elements of later comics was Rudolph Dirks’s “Katzenjammer Kids”, based on Wilhelm Busch’s Max and Moritz, a European satire of the nineteenth century. The “Kids” strip, first published in 1897, served as the prototype for future American strips. It contained not only speech baloons, but a continuous cast of characters, and was divided into small regular panels that did away with the larger panoramic scenes of earlier comics.
Newspaper syndication played a major role in spreading the popularity of comic strips throughout the country. Though weekly colored comics came first, daily black-and-white strips were not far behind. The first appeared in the Chicago American in 1904. It was followed by many imitators, and by 1915 black-and-white comic strips had become a staple of daily newspapers around the country.

In what order does the author discuss various comic strips in the passage?

Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage:

"Like any other universities, the Open University can give you a degree. However, you don’t have to (1)…. working to study. It can also open up a whole variety (2)….. interest. If you have (3)….. studied before, you will enjoy the special, new pleasure of (4)….. your knowledge. You will make friends of (5)….. kinds. You may also (6)…. that your qualification provides new career opportunities.
 You don’t actually (7)…. to the Open University for lectures, but study at home, using television, radio and Computer software. You can (8)….. one class a month if you wish at an Open University centre. Of course, there are exams to take, as in (9)…..  university. If you (10)….like to know more, all you have to do is to complete the form below. It could be the start of a wonderful new period in your life."

1. However, you don’t have to (1)…. working to study.

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:
Birds have evolved many physical attributes that contribute to their flying ability. Wings are important, but adjustable tails, large hearts and light bones play critical roles.
To fly, birds, like airplanes, move air across their wings. Wings are designed so that air above the wings is forced to move faster than air below the wing. This creates higher pressure under the wings, called lift, which pushes the bird up. Different wing types evolved for different ways of flying. Prolonged flight requires long wings and an ability to soar. Other birds need superior maneuverability. Finches and sparrows
have short, broad wings. Faster birds, like hawks, have built-in spoilers that reduce turbulence while flying. This allows a steeper angle of attack without stalling.
Tails have evolved for specialized use. The tail acts like a rudder helping birds steer. Birds brake by spreading out their tails as they land. This adaptation allows them to make sudden, controlled stops-an essential skill, since most birds need to land on individual branches or on prey.
Flight takes muscle strength. If body builders has wings, they still could not flap hard enough to leave the ground. Birds have large, specialized hearts that beat much faster than the human heart and
provide the necessary oxygen to the muscles. The breast muscle accounts for 15 percent of the bird’s body weight. On pigeons, it accounts for a third of their total body weight.
Birds carry no excess baggage; they have hollow feathers and hollow bones with struts inside to maintain strength, like cross beams in a bridge. Birds fly to find prey, escape predators, and attract mates- in other words, to survive.

According to the passage, what benefit comes from having built-in spoilers?

The end of December and the beginning of January are the busiest times for the Japanese post offices. (1) _________ Japanese have a custom of sending New Year’s Day postcards to their friends and relatives, (2) __________ to the Western custom of sending Christmas cards. Their original purpose was to give your faraway friends and relatives tidings of yourself and your immediate family. (3) __________, this custom existed for people to tell others whom they did not often meet that they were alive and well.

Japanese people send these postcards so that they arrive (4) ___________ 1st January. The post office guarantees (5) ______ the greeting postcards on 1st January if they are posted within a time limit. To deliver these cards (6) _________ time, the post office usually hires students part-time to help deliver the letters.

It is (7) _________ not to send these postcards when one has had a death in the family during the year. In this case, a family member sends a simple postcard (8) ____mochi hagaki (mourning postcards) to inform friends and relatives they should send New Year’s cards, out of respect for the deceased.

(6) _________

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:
Lighthouses are towers with strong lights that help mariners plot their position, inform them that  land is near, and warn them of dangerous rocks and reefs. They are placed at prominent points on the coast and on islands, reefs, and sandbars.
Every lighthouse has a distinctive pattern of light known as its characteristic. There are five basic characteristics: fixed, flashing, occulting, group flashing, and group occulting. A fixed signal is a steady beam. A flashing signal has periods of darkness longer than periods of light, while an occulting signal’s periods of light are longer. A group-flashing light gives off two or more flashes at regular intervals, and a group - occulting signal consists of a fixed light with two or more periods of darkness at regular intervals. Some lighthouses use lights of different colors as well, and today, most lighthouses are also equipped with radio beacons. The three types of apparatus used to produce the signals are the catoptric, in which metal is used to reflect the light; the dioptric, in which glass is used; and the catadioptric, in which both glass and metal are used.
In the daytime, lighthouses can usually be identified by their structure alone. The most typical structure is a tower tapering at the top, but some, such as the Bastion Lighthouse on the Saint Lawrence River, are shaped like pyramids, and others, such as the Race Rock light, look like wooden houses sitting on high platforms. Still others, such as The American Shoal lighthouse off the Florida Coast, are skeletal towers of steel. Where lighthouses might be contused in daylight, they can be distinguished by day- marker patterns - designed of checks and stripes painted in vivid colors on lighthouse walls.
In the past, the job of lighthouse keeper was lonely and difficult if somewhat romantic. Lighthouse keepers put in hours of tedious work maintaining the lights. Today, lighthouses are almost entirely automated with humans supplying only occasional maintenance. Because of improvements in navigational technology, the importance of lighthouses has diminished. There are only about 340
functioning lighthouses in existence in the United States today, compared to about 1,500 in 1900, and there are only about 1,400 functioning lighthouses outside the United States. Some decommissioned lighthouses have been preserved as historical monument.

According to the passage, what kind of signal has long periods of light that are regularly broken by two or more periods of darkness?