Cho hàm số . Đồ thị của hàm số  như hình vẽ bên. Số nghiệm thực của phương trình  là    

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:

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth on seater, so thay at 39 meters in seawater a diver is exposed to pressure of about 4 atmosphere. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmosphere, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect. As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints. Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend ang even rupture. This the rise of the exhaled air bubbles, and must exhale during ascent.

Question: The word “rupture” in bold in paragraph 3 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:

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 44: What 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:

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 45: According to the passage, one advantage of live interviews over questionnaires is that live interviews  

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 40: According to the passage, the main disadvantage of person-on-the-street interviews is that they______          

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 41: It can be inferred from the passage that one reason that sociologists may become frustrated with questionnaires is that______           

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 42: According to paragraph 3, which of the following is most important for an effective survey?  

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 43: The word "elicit" in line 18 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 45: The phrase “besieged by claims” in paragraph 3 can be understood as ______.         

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 44: The “welcome development” mentioned in paragraph 2 is an increase in ____.         

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:

Computers have led to a greater change in our society in recent decades than any other force and are likely to continue to do so until the next century. The industry surrounding computers is growing quickly, providing employment for many but meanwhile making others redundant. Jobs that computers can do much more reliably, faster and cheaper are lost. The redeployment of labour and the prospect of increased leisure are causing social upheavals which require new ideas and significant changes of attitude.

Question 41: As implied in the passage, the widespread use of computers in industry _______.