Cho hình phẳng $(H)$ giới hạn bởi các đường $y=2x-x^2,y=0$ . Khi $(H)$ quay xung quanh trục $Ox$ thu được khối tròn xoay có thể tích $V=\pi \left(\frac{a}{b}+1\right)$ , với $\frac{a}{b}$ là phân số tối giản. Khi đó $a.b$ bằng bao nhiêu?

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate to the word or phrase that best fits each of the numbered blanks from 1 to 5:

 The final stage before adulthood is adolescence. This is a period of transition for teenagers and there are many crucial milestones. Socially and emotionally, teens worry that they may not be developing at the same rate (1)_______ their peers. They become extremely self-conscious and may be sensitive about their appearance. Teens may rebel (2) ________ their parents but are also more able to accept the consequences of their actions. This is also a period of enormous physical changes and adolescent experience changes in their physical development at a rate unparalleled since infancy. These changes include significant gains in height and weight. Within a year, boys and girls can gain an (3)_________ of 4.1 inches and 3.5 inches repectively. This growth spurt typically 2 years earlier for girls than for boys and can tend to make both sexes go through a clumsy phase. (4)_________ their cognitive development, adolescents have greater reasoning skills and have developed the ability to think logically and hypothetically. They are also able to discuss more abstract concepts. They should also have (5)__________strategies to help them study.

Question 4:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate to the word or phrase that best fits each of the numbered blanks from 1 to 5:

 The final stage before adulthood is adolescence. This is a period of transition for teenagers and there are many crucial milestones. Socially and emotionally, teens worry that they may not be developing at the same rate (1)_______ their peers. They become extremely self-conscious and may be sensitive about their appearance. Teens may rebel (2) ________ their parents but are also more able to accept the consequences of their actions. This is also a period of enormous physical changes and adolescent experience changes in their physical development at a rate unparalleled since infancy. These changes include significant gains in height and weight. Within a year, boys and girls can gain an (3)_________ of 4.1 inches and 3.5 inches repectively. This growth spurt typically 2 years earlier for girls than for boys and can tend to make both sexes go through a clumsy phase. (4)_________ their cognitive development, adolescents have greater reasoning skills and have developed the ability to think logically and hypothetically. They are also able to discuss more abstract concepts. They should also have (5)__________strategies to help them study.

Question 5:

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate to the word or phrase that best fits each of the numbered blanks from 1 to 5:

 The final stage before adulthood is adolescence. This is a period of transition for teenagers and there are many crucial milestones. Socially and emotionally, teens worry that they may not be developing at the same rate (1)_______ their peers. They become extremely self-conscious and may be sensitive about their appearance. Teens may rebel (2) ________ their parents but are also more able to accept the consequences of their actions. This is also a period of enormous physical changes and adolescent experience changes in their physical development at a rate unparalleled since infancy. These changes include significant gains in height and weight. Within a year, boys and girls can gain an (3)_________ of 4.1 inches and 3.5 inches repectively. This growth spurt typically 2 years earlier for girls than for boys and can tend to make both sexes go through a clumsy phase. (4)_________ their cognitive development, adolescents have greater reasoning skills and have developed the ability to think logically and hypothetically. They are also able to discuss more abstract concepts. They should also have (5)__________strategies to help them study.

Question 1:

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 from 31 to 35:

GLOBAL WARMING

Few people now question the reality of global warming and its effects on the world’s climate. Many scientists (31) ________ the blame for recent natural disasters on the increase in the world’s temperatures and are convinced that, more than ever before, the Earth is at risk from the forces of the wind, rain and sun. (32) ________ to them, global warming is making extreme weather events, such as hurricanes and droughts, even more (33) ________ and causing sea levels all around the world to rise. Environmental groups are putting pressure on governments to take action to reduce the amount of carbon dioxide which is given (34) ________ by factories and power plants, thus attacking the problem at its source. They are in favor of more money being spent on research into solar, wind and wave energy devices, which could then replace existing power station. Some scientists, (35) ________, believe that even if we stopped releasing carbon dioxide and other gases into the atmosphere tomorrow, we would have to wait several hundred years to notice the results. Global warming, it seems, is to stay.  

Question 35:        

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 from 31 to 35:

GLOBAL WARMING

Few people now question the reality of global warming and its effects on the world’s climate. Many scientists (31) ________ the blame for recent natural disasters on the increase in the world’s temperatures and are convinced that, more than ever before, the Earth is at risk from the forces of the wind, rain and sun. (32) ________ to them, global warming is making extreme weather events, such as hurricanes and droughts, even more (33) ________ and causing sea levels all around the world to rise. Environmental groups are putting pressure on governments to take action to reduce the amount of carbon dioxide which is given (34) ________ by factories and power plants, thus attacking the problem at its source. They are in favor of more money being spent on research into solar, wind and wave energy devices, which could then replace existing power station. Some scientists, (35) ________, believe that even if we stopped releasing carbon dioxide and other gases into the atmosphere tomorrow, we would have to wait several hundred years to notice the results. Global warming, it seems, is to stay.

Question 34:        

Reading the following passage and mark the letter A,B,C or D on your anwer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The latest addiction to trap thousands of people is the Internet, which has been (31)____ for broken relationships, job losses, financial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrom (IAS) as a new illness that could (32)______ serious problems and ruin many lives. Special help groups have been set up to offer suffers help and support. IAS is similar to (33)_____ problems like gambling, smoking and drinking: addicts have dreams about the Internet, they need to use it first thing in the morning; they lie to their partner about how much time they spend online; they wish they could cut down, but are unable to do so. A recent study found that many users spend up to 40 hours a week on the Internet; although they felt guilty, they became depressed if they were (34) ___________ to stop using it. Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on computer games and who (35) ___________ it very difficult to resist the games on the Internet. Surprisingly, however, psychologists say that most victims are middle-aged housewives who have never used a computer before.  

Question 31:

Reading the following passage and mark the letter A,B,C or D on your anwer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The latest addiction to trap thousands of people is the Internet, which has been (31)____ for broken relationships, job losses, financial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrom (IAS) as a new illness that could (32)______ serious problems and ruin many lives. Special help groups have been set up to offer suffers help and support. IAS is similar to (33)_____ problems like gambling, smoking and drinking: addicts have dreams about the Internet, they need to use it first thing in the morning; they lie to their partner about how much time they spend online; they wish they could cut down, but are unable to do so. A recent study found that many users spend up to 40 hours a week on the Internet; although they felt guilty, they became depressed if they were (34) ___________ to stop using it. Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on computer games and who (35) ___________ it very difficult to resist the games on the Internet. Surprisingly, however, psychologists say that most victims are middle-aged housewives who have never used a computer before.  

Question 32:

Reading the following passage and mark the letter A,B,C or D on your anwer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The latest addiction to trap thousands of people is the Internet, which has been (31)____ for broken relationships, job losses, financial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrom (IAS) as a new illness that could (32)______ serious problems and ruin many lives. Special help groups have been set up to offer suffers help and support. IAS is similar to (33)_____ problems like gambling, smoking and drinking: addicts have dreams about the Internet, they need to use it first thing in the morning; they lie to their partner about how much time they spend online; they wish they could cut down, but are unable to do so. A recent study found that many users spend up to 40 hours a week on the Internet; although they felt guilty, they became depressed if they were (34) ___________ to stop using it. Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on computer games and who (35) ___________ it very difficult to resist the games on the Internet. Surprisingly, however, psychologists say that most victims are middle-aged housewives who have never used a computer before.  

Question 33:

Reading the following passage and mark the letter A,B,C or D on your anwer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The latest addiction to trap thousands of people is the Internet, which has been (31)____ for broken relationships, job losses, financial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrom (IAS) as a new illness that could (32)______ serious problems and ruin many lives. Special help groups have been set up to offer suffers help and support. IAS is similar to (33)_____ problems like gambling, smoking and drinking: addicts have dreams about the Internet, they need to use it first thing in the morning; they lie to their partner about how much time they spend online; they wish they could cut down, but are unable to do so. A recent study found that many users spend up to 40 hours a week on the Internet; although they felt guilty, they became depressed if they were (34) ___________ to stop using it. Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on computer games and who (35) ___________ it very difficult to resist the games on the Internet. Surprisingly, however, psychologists say that most victims are middle-aged housewives who have never used a computer before.  

Question 34:

Reading the following passage and mark the letter A,B,C or D on your anwer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The latest addiction to trap thousands of people is the Internet, which has been (31)____ for broken relationships, job losses, financial ruin and even one suicide. Psychologists now recognize Internet Addiction Syndrom (IAS) as a new illness that could (32)______ serious problems and ruin many lives. Special help groups have been set up to offer suffers help and support. IAS is similar to (33)_____ problems like gambling, smoking and drinking: addicts have dreams about the Internet, they need to use it first thing in the morning; they lie to their partner about how much time they spend online; they wish they could cut down, but are unable to do so. A recent study found that many users spend up to 40 hours a week on the Internet; although they felt guilty, they became depressed if they were (34) ___________ to stop using it. Almost anyone can be at risk. Some of the addicts are teenagers who are already hooked on computer games and who (35) ___________ it very difficult to resist the games on the Internet. Surprisingly, however, psychologists say that most victims are middle-aged housewives who have never used a computer before.  

Question 35: