Mặt chân đế của vật là

Một vật rắn khi kéo vật ra khỏi vị trí cân bằng một chút thì trọng lực có xu hướng kéo vật ra xa vị trí cân bằng cũ của nó là cân bằng

Vật càng cân bằng khi

Vật nằm yên trên mặt bàn nằm ngang thì

Cân bằng của vật rắn  

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 penny press, which emerged in the United States during the 1830's, was a powerful agent of mass communication. These newspapers were little dailies, generally four pages in length, written for the mass taste. They differed from the staid, formal presentation of the conservative press, with its emphasis on political and literary topics. The new papers were brief and cheap, emphasizing sensational reports of police courts and juicy scandals as well as human interest stories. Twentieth-century journalism was already foreshadowed in the penny press of the 1830's. The New York Sun, founded in 1833, was the first successful penny paper, and it was followed two years later by the New York Herald, published by James Gordon Bennett. Not long after, Horace Greeley issued the New York Tribune, which was destined to become the most influential paper in America. Greeley gave space to the issues that deeply touched the American people before the Civil War-abolitionism, temperance, free homesteads, Utopian cooperative settlements, and the problems of labor. The weekly edition of the Tribune, with 100,000 subscribers, had a remarkable influence in rural areas, especially in Western communities. Americans were reputed to be the most avid readers of periodicals in the world. An English observer enviously calculated that, in 1829, the number of newspapers circulated in Great Britain was enough to reach only one out of every thirty-six inhabitants weekly; Pennsylvania in that same year had a newspaper circulation which reached one out of every four inhabitants weekly. Statistics seemed to justify the common belief that Americans were devoted to periodicals. Newspapers in the United States increased from 1,200 in 1833 to 3,000 by the early 1860's, on the eve of the Civil War. This far exceeded the number and circulation of newspapers in England and France.

Question 39: Who was Horace Greeley?         

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 penny press, which emerged in the United States during the 1830's, was a powerful agent of mass communication. These newspapers were little dailies, generally four pages in length, written for the mass taste. They differed from the staid, formal presentation of the conservative press, with its emphasis on political and literary topics. The new papers were brief and cheap, emphasizing sensational reports of police courts and juicy scandals as well as human interest stories. Twentieth-century journalism was already foreshadowed in the penny press of the 1830's. The New York Sun, founded in 1833, was the first successful penny paper, and it was followed two years later by the New York Herald, published by James Gordon Bennett. Not long after, Horace Greeley issued the New York Tribune, which was destined to become the most influential paper in America. Greeley gave space to the issues that deeply touched the American people before the Civil War-abolitionism, temperance, free homesteads, Utopian cooperative settlements, and the problems of labor. The weekly edition of the Tribune, with 100,000 subscribers, had a remarkable influence in rural areas, especially in Western communities. Americans were reputed to be the most avid readers of periodicals in the world. An English observer enviously calculated that, in 1829, the number of newspapers circulated in Great Britain was enough to reach only one out of every thirty-six inhabitants weekly; Pennsylvania in that same year had a newspaper circulation which reached one out of every four inhabitants weekly. Statistics seemed to justify the common belief that Americans were devoted to periodicals. Newspapers in the United States increased from 1,200 in 1833 to 3,000 by the early 1860's, on the eve of the Civil War. This far exceeded the number and circulation of newspapers in England and France.

Question 38: The word “it” in paragraph 2 refers 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:

Broad-tailed hummingbirds often nest in quaking, slender deciduous trees with smooth, gray-green bark found in the Colorado Rockies of the Western United States. After flying some 2,000 kilometres north from where they have wintered in Mexico, the hummingbirds need six weeks to build a nest, incubate their eggs, and raise the chicks. A second nest is feasible only if the first fails early in the season. Quality, not quantity, is what counts in hummingbird reproduction. A nest on the lowest intact branch of an aspen will give a hummingbird a good view, a clear flight patch, and protection for her young. Male hummingbirds claim feeding territories in open meadows where, from late May through June, they mate with females coming to feed but take no part in nesting. Thus when the hen is away to feed, the nest is unguarded. While the smooth bark of the aspen trunk generally offers a poor grip for the claws of a hungry squirrel or weasel, aerial attacks, from a hawk, owl, or gray jay, are more likely. The choice of where to build a nest is based not only on the branch itself but also on what hangs over it. A crooked deformity in the nest branch, a second, unusually close branch overhead, or proximity to part of a trunk bowed by a past ice storm are features that provide shelter and make for an attractive nest site. Scarcely larger than a halved golf ball, the nest is painstaking constructed of spider webs and plant down, decorated and camouflaged outside with paper-like bits of aspen bark held together with more strands of spider silk. By early June it will hold two pea-sized eggs, which each weigh one-seventh of the mother's weight, and in sixteen to nineteen days, two chicks.

Question: What aspect of broad-tailed hummingbird behaviour does the passage mainly discuss?         

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 a number of natural disasters that can strike across the globe. Two that are frequently linked to one another are earthquakes and tsunamis. Both of them can cause a great amount of devastation when they hit. However, tsunamis are the direct result of earthquakes and cannot happen without them.

The Earth has three main parts. They are the crust, the mantle, and the core. The crust is the outer layer of the Earth. It is not a single piece of land. Instead, it is comprised of a number of plates. There are a few enormous plates and many smaller ones. These plates essentially rest upon the mantle, which is fluid. As a result, the plates are in constant - yet slow - motion. The plates may move away from or toward other plates. In some cases, they collide violently with the plates adjoining them. The movement of the plates causes tension in the rock. Over a long time, this tension may build up. When it is released, an earthquake happens.

Tens of thousands of earthquakes happen every year. The vast majority are so small that only scientific instruments can perceive them. Others are powerful enough that people can feel them, yet they cause little harm or damage. More powerful earthquakes, however, can cause buildings, bridges, and other structures to collapse. They may additionally injure and kill thousands of people and might even cause the land to change its appearance.

Since most of the Earth’s surface is water, numerous earthquakes happen beneath the planet’s oceans. Underwater earthquakes can cause the seafloor to move. This results in the displacement of water in the ocean. When this occurs, a tsunami may form. This is a wave that forms on the surface and moves in all directions from the place where the earthquake happened. A tsunami moves extremely quickly and can travel thousands of kilometres. As it approaches land, the water near the coast gets sucked out to sea. This causes the tsunami to increase in height. Minutes later, the tsunami arrives. A large tsunami - one more than ten meters in height - can travel far inland. As it does that, it can flood the land, destroy human settlements, and kill large numbers of people.

Question: Which of the following statements does paragraph 1 support?

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 a number of natural disasters that can strike across the globe. Two that are frequently linked to one another are earthquakes and tsunamis. Both of them can cause a great amount of devastation when they hit. However, tsunamis are the direct result of earthquakes and cannot happen without them.

The Earth has three main parts. They are the crust, the mantle, and the core. The crust is the outer layer of the Earth. It is not a single piece of land. Instead, it is comprised of a number of plates. There are a few enormous plates and many smaller ones. These plates essentially rest upon the mantle, which is fluid. As a result, the plates are in constant - yet slow - motion. The plates may move away from or toward other plates. In some cases, they collide violently with the plates adjoining them. The movement of the plates causes tension in the rock. Over a long time, this tension may build up. When it is released, an earthquake happens.

Tens of thousands of earthquakes happen every year. The vast majority are so small that only scientific instruments can perceive them. Others are powerful enough that people can feel them, yet they cause little harm or damage. More powerful earthquakes, however, can cause buildings, bridges, and other structures to collapse. They may additionally injure and kill thousands of people and might even cause the land to change its appearance.

Since most of the Earth’s surface is water, numerous earthquakes happen beneath the planet’s oceans. Underwater earthquakes can cause the seafloor to move. This results in the displacement of water in the ocean. When this occurs, a tsunami may form. This is a wave that forms on the surface and moves in all directions from the place where the earthquake happened. A tsunami moves extremely quickly and can travel thousands of kilometres. As it approaches land, the water near the coast gets sucked out to sea. This causes the tsunami to increase in height. Minutes later, the tsunami arrives. A large tsunami - one more than ten meters in height - can travel far inland. As it does that, it can flood the land, destroy human settlements, and kill large numbers of people.

Question: 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:

There are a number of natural disasters that can strike across the globe. Two that are frequently linked to one another are earthquakes and tsunamis. Both of them can cause a great amount of devastation when they hit. However, tsunamis are the direct result of earthquakes and cannot happen without them.

The Earth has three main parts. They are the crust, the mantle, and the core. The crust is the outer layer of the Earth. It is not a single piece of land. Instead, it is comprised of a number of plates. There are a few enormous plates and many smaller ones. These plates essentially rest upon the mantle, which is fluid. As a result, the plates are in constant - yet slow - motion. The plates may move away from or toward other plates. In some cases, they collide violently with the plates adjoining them. The movement of the plates causes tension in the rock. Over a long time, this tension may build up. When it is released, an earthquake happens.

Tens of thousands of earthquakes happen every year. The vast majority are so small that only scientific instruments can perceive them. Others are powerful enough that people can feel them, yet they cause little harm or damage. More powerful earthquakes, however, can cause buildings, bridges, and other structures to collapse. They may additionally injure and kill thousands of people and might even cause the land to change its appearance.

Since most of the Earth’s surface is water, numerous earthquakes happen beneath the planet’s oceans. Underwater earthquakes can cause the seafloor to move. This results in the displacement of water in the ocean. When this occurs, a tsunami may form. This is a wave that forms on the surface and moves in all directions from the place where the earthquake happened. A tsunami moves extremely quickly and can travel thousands of kilometres. As it approaches land, the water near the coast gets sucked out to sea. This causes the tsunami to increase in height. Minutes later, the tsunami arrives. A large tsunami - one more than ten meters in height - can travel far inland. As it does that, it can flood the land, destroy human settlements, and kill large numbers of people.

Question: The word “It” in bold in paragraph 2 refers 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:

A survey is a study, generally in the form of an interview or a ques­tionnaire, which provides information concerning how people think and act. In the United States, the best-known surveys are the Gallup poll and the Harris poll. As anyone who watches the news during presiden­tial campaigns knows, these polls have become an important part of political life in the United States.

North Americans are familiar with the many "person on the street" interviews on local television news shows. While such interviews can be highly entertaining, they are not necessarily an accurate indication of public opinion. First, they reflect the opinions of only those people who appear at a certain location. Thus, such samples can be biased in favor of commuters, middle-class shoppers, or factory workers, depending on which area the new people select. Second, television interviews tend to attract outgoing people who are willing to appear on the air, while they frighten away others who may feel intimidated by a camera. A survey must be based on a precise, representative sampling if it is to genu­inely reflect a broad range of the population.

In preparing to conduct a survey, sociologists must exercisegreat care in the wording of questions. An effective survey question must be simple and clear enough for people to understand it. It must also be specific enough so that there are no problems in interpreting the re­sults. Even questions that are less structured must be carefully phrased in order to elicitthe type of information desired. Surveys can be indispensable sources of information, but only if the sampling is done properly and the questions are worded accurately.

There are two main forms of surveys: the interview and the ques­tionnaire. Each of these forms of survey research has its advantages. An interviewer can obtain a high response rate because people find it more difficult to turn down a personal request for an interview than to throw away a written questionnaire. In addition, an interviewer can go beyond written questions and probefor a subject's underlying feelings and reasons. However, questionnaires have the advantage of being cheaper and more consistent.

Question 46: Which of the following terms is defined in 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 questions:

A survey is a study, generally in the form of an interview or a ques­tionnaire, which provides information concerning how people think and act. In the United States, the best-known surveys are the Gallup poll and the Harris poll. As anyone who watches the news during presiden­tial campaigns knows, these polls have become an important part of political life in the United States.

North Americans are familiar with the many "person on the street" interviews on local television news shows. While such interviews can be highly entertaining, they are not necessarily an accurate indication of public opinion. First, they reflect the opinions of only those people who appear at a certain location. Thus, such samples can be biased in favor of commuters, middle-class shoppers, or factory workers, depending on which area the new people select. Second, television interviews tend to attract outgoing people who are willing to appear on the air, while they frighten away others who may feel intimidated by a camera. A survey must be based on a precise, representative sampling if it is to genu­inely reflect a broad range of the population.

In preparing to conduct a survey, sociologists must exercisegreat care in the wording of questions. An effective survey question must be simple and clear enough for people to understand it. It must also be specific enough so that there are no problems in interpreting the re­sults. Even questions that are less structured must be carefully phrased in order to elicitthe type of information desired. Surveys can be indispensable sources of information, but only if the sampling is done properly and the questions are worded accurately.

There are two main forms of surveys: the interview and the ques­tionnaire. Each of these forms of survey research has its advantages. An interviewer can obtain a high response rate because people find it more difficult to turn down a personal request for an interview than to throw away a written questionnaire. In addition, an interviewer can go beyond written questions and probefor a subject's underlying feelings and reasons. However, questionnaires have the advantage of being cheaper and more consistent.

Question 47: The word "exercise" in line 15 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:

Are organically grown foods the best choices? The advantage claimed for such foods over conventionally grown and marketed food products are now being debated. Advocates of organic foods - a term whose meaning varies greatly - frequently proclaim that such products are safer and more nutritious than others. The growing interest of consumers in the safety and nutritional quality of the typical North American diet is a welcome development. However, much of this interest has been sparked by sweeping claims that the food supply is unsafe or inadequate in meeting nutritional evidence, the preponderance of written material advancing. As a result, claims that eating a diet consisting of entirely organically grown foods prevents or cures diseases provides other benefits to health have become widely publicized and form the basis for folklore. Almost daily, the public is besieged by claims for “no - aging” diets, new vitamins, and other wonder foods. There are numerous unsubstantiated reports that natural to unfertilized eggs, that untreated grains are better than fumigated grains, and the like. One thing that most organically grown food products seem to have in common is that they cost more than conventionally grown foods. But in many cases, consumers misled if they believe organic foods can maintain health and provide better nutritional quality than conventionally grown foods. So there is real cause for concern if consumers particularly those with limited incomes, distrust the regular food supply and buy only expensive organic foods instead.

Question 50: What is the author’s attitude toward the claims made by advocates of health foods?         

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:

Are organically grown foods the best choices? The advantage claimed for such foods over conventionally grown and marketed food products are now being debated. Advocates of organic foods - a term whose meaning varies greatly - frequently proclaim that such products are safer and more nutritious than others. The growing interest of consumers in the safety and nutritional quality of the typical North American diet is a welcome development. However, much of this interest has been sparked by sweeping claims that the food supply is unsafe or inadequate in meeting nutritional evidence, the preponderance of written material advancing. As a result, claims that eating a diet consisting of entirely organically grown foods prevents or cures diseases provides other benefits to health have become widely publicized and form the basis for folklore. Almost daily, the public is besieged by claims for “no - aging” diets, new vitamins, and other wonder foods. There are numerous unsubstantiated reports that natural to unfertilized eggs, that untreated grains are better than fumigated grains, and the like. One thing that most organically grown food products seem to have in common is that they cost more than conventionally grown foods. But in many cases, consumers misled if they believe organic foods can maintain health and provide better nutritional quality than conventionally grown foods. So there is real cause for concern if consumers particularly those with limited incomes, distrust the regular food supply and buy only expensive organic foods instead.

Question 47: The word “maintain” in the last paragraph is closest in meaning to______.