Một gen ở sinh vật nhân sơ có tổng số 3200 nucleotit trong đó số nucleotit loại A của gen chiếm 24%. Trên mạch đơn thứ nhất của gen có A1= 15% và G1 = 26%. Theo lý thuyết có bao nhiêu phát biểu sau đây là đúng khi nói về gen trên ?

I. gen có tỷ lệ A/G = 12/13

II. trên mạch thứ nhất của gen có T/G = 33/26

III. trên mạch thứ 2 của gen có G/A = 15/26

IV. khi gen tự nhân đôi 2 lần, môi trường đã cung cấp 2304 nucleotit loại adenin.

Nếu thì n có giá trị 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 from 41 to 48:

Another critical factor that plays a part in susceptibility to colds is age. A study done by the University of Michigan School of Public Health revealed particulars that seem to hold true for the general population. Infants are the most cold-ridden group, averaging more than six colds in their first year. Boys have more colds than girls up to age three. After the age of three, girls are more susceptible than boy's, and teenege girls average three colds a year to boy’s two. The general incidence of continues to decline into maturity. Elderly people who are in good health have as few as one or two colds annually. One exception is founds among people in the twentics, especially women, who show a rise in cold infections, because people in this age group are most likely to have young children. Adults who delay having children until thirties forties experience the same sudden increase in cold infections. The study also found that economics play an important role. As income increases, the frequency at which are reported in the family decreases. Families with the lowest income suffer about a third more colds than families at the lower end. Lower income generally forces people to live in more cramped quarters than those typically occupied by wealthier by wealthier people, and crowding increses the opportunities for the cold virus totravel from person to person. Low income may also adversely influence diet. The degree to which poor nutrition affects susceptibility to colds is not yet clearly established, but an inadequate diet is suspected of lowering resistance generally. (source: TOEFL reading)  

Question 46: The author’s main purpose in writing the last paragraph of the passage is to_______         

Hệ số của x8 trong khai triển biểu thức thành đa thức bằng:                         

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 below:

 Choosing a career may be one of the hardest jobs you ever have, and it must be done with care. View a career as an opportunity to do something you love, not simply as a way to earn a living. Investing the time and effort to thoroughly explore your options can mean the difference between finding a stimulating and rewarding career and move from job to unsatisfying job in an attempt to find the right one. Work influences virtually every aspect of your life, from your choice of friends to where you live. Here are just a few of the factors to consider.

 Deciding what matters most to you is essential to making the right decision. You may want to begin by assessing your likes, dislikes, strengths, and weaknesses. Think about the classes, hobbies, and surroundings that you find most appealing. Ask yourself questions, such as "Would you like to travel? Do you want to work with children? Are you more suited to solitary or cooperative work?" There are no right or wrong answers; only you know what is important to you. Determine which job features you require, which ones you would prefer, and which ones you cannot accept. Then rank them in order of importance to you.

 The setting of the job is one factor to take into account. You may not want to sit at a desk all day. If not, there are diversity occupation - building inspector, supervisor, real estate agent - that involve a great deal of time away from the office. Geographical location may be a concern, and employment in some fields is concentrated in certain regions. Advertising job can generally be found only in large cities. On the other hand, many industries such as hospitality, law education, and retail sales are found in all regions of the country.

 If a high salary is important to you, do not judge a career by its starting wages. Many jobs, such as insurance sales, offers relatively low starting salaries; however, pay substantially increases along with your experience, additional training, promotions and commission.

 Don’t rule out any occupation without learning more about it. Some industries evoke positive or negative associations. The traveling life of a flight attendant appears glamorous, while that of a plumber does not. Remember that many jobs are not what they appear to be at first, and may have merits or demerits that are less obvious. Flight attendants must work long, grueling hours without sleeps, whereas plumbers can be as highly paid as some doctors. Another point to consider is that as you get mature, you will likely to develop new interests and skills that may point the way to new opportunities. The choice you make today need not be your final one.

Question 29: The word “them” 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 below:

 Choosing a career may be one of the hardest jobs you ever have, and it must be done with care. View a career as an opportunity to do something you love, not simply as a way to earn a living. Investing the time and effort to thoroughly explore your options can mean the difference between finding a stimulating and rewarding career and move from job to unsatisfying job in an attempt to find the right one. Work influences virtually every aspect of your life, from your choice of friends to where you live. Here are just a few of the factors to consider.

 Deciding what matters most to you is essential to making the right decision. You may want to begin by assessing your likes, dislikes, strengths, and weaknesses. Think about the classes, hobbies, and surroundings that you find most appealing. Ask yourself questions, such as "Would you like to travel? Do you want to work with children? Are you more suited to solitary or cooperative work?" There are no right or wrong answers; only you know what is important to you. Determine which job features you require, which ones you would prefer, and which ones you cannot accept. Then rank them in order of importance to you.

 The setting of the job is one factor to take into account. You may not want to sit at a desk all day. If not, there are diversity occupation - building inspector, supervisor, real estate agent - that involve a great deal of time away from the office. Geographical location may be a concern, and employment in some fields is concentrated in certain regions. Advertising job can generally be found only in large cities. On the other hand, many industries such as hospitality, law education, and retail sales are found in all regions of the country.

 If a high salary is important to you, do not judge a career by its starting wages. Many jobs, such as insurance sales, offers relatively low starting salaries; however, pay substantially increases along with your experience, additional training, promotions and commission.

 Don’t rule out any occupation without learning more about it. Some industries evoke positive or negative associations. The traveling life of a flight attendant appears glamorous, while that of a plumber does not. Remember that many jobs are not what they appear to be at first, and may have merits or demerits that are less obvious. Flight attendants must work long, grueling hours without sleeps, whereas plumbers can be as highly paid as some doctors. Another point to consider is that as you get mature, you will likely to develop new interests and skills that may point the way to new opportunities. The choice you make today need not be your final one.

Question 30: The word "assessing” in paragraph 2 could best be replaced by _______.         

Biết n là số nguyên dương thỏa mãn . Giá trị của n 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 below:

 Choosing a career may be one of the hardest jobs you ever have, and it must be done with care. View a career as an opportunity to do something you love, not simply as a way to earn a living. Investing the time and effort to thoroughly explore your options can mean the difference between finding a stimulating and rewarding career and move from job to unsatisfying job in an attempt to find the right one. Work influences virtually every aspect of your life, from your choice of friends to where you live. Here are just a few of the factors to consider.

 Deciding what matters most to you is essential to making the right decision. You may want to begin by assessing your likes, dislikes, strengths, and weaknesses. Think about the classes, hobbies, and surroundings that you find most appealing. Ask yourself questions, such as "Would you like to travel? Do you want to work with children? Are you more suited to solitary or cooperative work?" There are no right or wrong answers; only you know what is important to you. Determine which job features you require, which ones you would prefer, and which ones you cannot accept. Then rank them in order of importance to you.

 The setting of the job is one factor to take into account. You may not want to sit at a desk all day. If not, there are diversity occupation - building inspector, supervisor, real estate agent - that involve a great deal of time away from the office. Geographical location may be a concern, and employment in some fields is concentrated in certain regions. Advertising job can generally be found only in large cities. On the other hand, many industries such as hospitality, law education, and retail sales are found in all regions of the country.

 If a high salary is important to you, do not judge a career by its starting wages. Many jobs, such as insurance sales, offers relatively low starting salaries; however, pay substantially increases along with your experience, additional training, promotions and commission.

 Don’t rule out any occupation without learning more about it. Some industries evoke positive or negative associations. The traveling life of a flight attendant appears glamorous, while that of a plumber does not. Remember that many jobs are not what they appear to be at first, and may have merits or demerits that are less obvious. Flight attendants must work long, grueling hours without sleeps, whereas plumbers can be as highly paid as some doctors. Another point to consider is that as you get mature, you will likely to develop new interests and skills that may point the way to new opportunities. The choice you make today need not be your final one.

Question 31: According to paragraph 3, which of the following fields is NOT suitable for a person who does not want to live in a big city?  

Lớp 11A7 có 18 học sinh nam và 24 học sinh nữ. Thầy chủ nhiệm cần chọn 10 học sinh để luyện tập vũ khúc sân trường. Hỏi thầy chủ nhiệm có bao nhiêu cách chọn 10 học sinh sao cho có ít nhất 1 học sinh nữ?                         

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 below:

 Choosing a career may be one of the hardest jobs you ever have, and it must be done with care. View a career as an opportunity to do something you love, not simply as a way to earn a living. Investing the time and effort to thoroughly explore your options can mean the difference between finding a stimulating and rewarding career and move from job to unsatisfying job in an attempt to find the right one. Work influences virtually every aspect of your life, from your choice of friends to where you live. Here are just a few of the factors to consider.

 Deciding what matters most to you is essential to making the right decision. You may want to begin by assessing your likes, dislikes, strengths, and weaknesses. Think about the classes, hobbies, and surroundings that you find most appealing. Ask yourself questions, such as "Would you like to travel? Do you want to work with children? Are you more suited to solitary or cooperative work?" There are no right or wrong answers; only you know what is important to you. Determine which job features you require, which ones you would prefer, and which ones you cannot accept. Then rank them in order of importance to you.

 The setting of the job is one factor to take into account. You may not want to sit at a desk all day. If not, there are diversity occupation - building inspector, supervisor, real estate agent - that involve a great deal of time away from the office. Geographical location may be a concern, and employment in some fields is concentrated in certain regions. Advertising job can generally be found only in large cities. On the other hand, many industries such as hospitality, law education, and retail sales are found in all regions of the country.

 If a high salary is important to you, do not judge a career by its starting wages. Many jobs, such as insurance sales, offers relatively low starting salaries; however, pay substantially increases along with your experience, additional training, promotions and commission.

 Don’t rule out any occupation without learning more about it. Some industries evoke positive or negative associations. The traveling life of a flight attendant appears glamorous, while that of a plumber does not. Remember that many jobs are not what they appear to be at first, and may have merits or demerits that are less obvious. Flight attendants must work long, grueling hours without sleeps, whereas plumbers can be as highly paid as some doctors. Another point to consider is that as you get mature, you will likely to develop new interests and skills that may point the way to new opportunities. The choice you make today need not be your final one.

Question 32: It can be inferred from the paragraph 3 that _______.