Một loài vi khuẩn có thời gian thế hệ là 30 phút, cấy 200 tế bào vào một môi trường nuôi cấy thì thấy pha cân bằng đạt được sau 7 giờ với tổng số tế bào là 1638400. Phát biểu nào sau đây là đúng?

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

All mammals feed their young. Beluga whale mothers, for example, nurse their calves for some twenty months, until they are about to give birth again and their young are able to find their own food. The behavior of feeding of the young is built into the reproductive system. It is a nonelective part of parental care and the defining feature of a mammal, the most important thing that mammals-- whether marsupials, platypuses, spiny anteaters, or placental mammals -- have in common.

But not all animal parents, even those that tend their offspring to the point of hatching or birth, feed their young. Most egg-guarding fish do not, for the simple reason that their young are so much smaller than the parents and eat food that is also much smaller than the food eaten by adults. In reptiles, the crocodile mother protects her young after they have hatched and takes them down to the water, where they will find food, but she does not actually feed them. Few insects feed their young after hatching, but some make other arrangement, provisioning their cells and nests with caterpillars and spiders that they have paralyzed with their venom and stored in a state of suspended animation so that their larvae might have a supply of fresh food when they hatch.

For animals other than mammals, then, feeding is not intrinsic to parental care. Animals add it to their reproductive strategies to give them an edge in their lifelong quest for descendants. The most vulnerable moment in any animal's life is when it first finds itself completely on its own, when it must forage and fend for itself. Feeding postpones that moment until a young animal has grown to such a size that it is better able to cope. Young that are fed by their parents become nutritionally independent at a much greater fraction of their full adult size. And in the meantime those young are shielded against the vagaries of fluctuating of difficult-to-find supplies. Once a species does take the step of feeding its young, the young become totally dependent on the extra effort. If both parents are removed, the young generally do not survive.

Question: 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 below:

 Baseball evolved from a number of different ball-and-stick games (paddle ball, trap ball, one-old-cat, rounders, and town ball) originating in England. As early as the American Revolution, it was noted that troops played “baseball" in their free time. In 1845 Alexander Cartwright formalized the New York Knickerbockers’ version of the game: a diamond shaped infield, with bases ninety feet apart, three strikes-you’re-out, batter out on a caught ball, three outs per inning, a nine-man team. The “New York Game” spread rapidly, replacing earlier localized forms. From its beginnings, baseball was seen as a way of satisfying the recreational needs of an increasingly urban-industrial society. At its inception it was played by and for wealthy gentlemen. A club might consist of 40 members. The president would appoint two captains who would choose teams from among the members. Games were played on Monday and Thursday afternoons, with the losers often providing a lavish evening’s entertainment for the winners.

 During the 1850-70 period the game was changing; however, with increasing commercialism (charging admission), under-the-table payments to exceptional players, and gambling on the outcome of games. By 1868 it was said that a club would have their regular professional ten, an amateur first-nine, and their "muffins" (the gentlemanly duffers who once ran the game). Beginning with the first openly all-salaried team (Cincinnati’s Red Stocking Club) in 1869, the 1870-1890 period saw the complete professionalization of baseball, including formation of the National Association of Professional Baseball Players in 1871. The National League of Professional Base Ball Clubs was formed in 1876, run by business-minded investors in joint-stock company clubs. The 1880s has been called Major League Baseball’s “Golden Age”. Profits soared, player’s salaries rose somewhat, a season of 84 games became one of 132, a weekly periodical “The Sporting News” came into being, wooden stadiums with double-deck stands replaced open fields, and the standard refreshment became hot dogs, soda pop and peanuts. In 1900 the Western League based in the growing cities of the Midwest proclaimed itself the American League.

Question 43: The word "itself" 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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: According to the passage, which of the following is a universal rule of etiquette?           

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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

Question: According to the passage, what requires sensitivity and experience?         

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 following question from 36 to 43:

 A number of factors related to the voice reveal the personality of the speaker. The first is the broad area of communication, which includes imparting information by use of language, communicating with a group or an individual and specialized communication through performance. A person conveys thoughts and ideas through choice of words, by a tone of voice that is pleasant or unpleasant, gentle or harsh, by the rhythm that is inherent within the language itself, and by speech rhythms that are flowing and regular or uneven and hesitant, and finally, by the pitch and melody of the utterance. When speaking before a group, a person's tone may indicate uncertainty or fright, confidence or calm. At interpersonal levels, the tone may reflect ideas and feelings over and above the words chosen, or may belie them. Here the participant’s tone can consciously or unconsciously reflect intuitive sympathy or antipathy, lack of concern or interest, fatigue, anxiety, enthusiasm or excitement, all of which are usually discernible by the acute listener. Public performance is a manner of communication that is highly specialized with its own techniques for obtaining effects by voice and/ or gesture. The motivation derived from the text, and in the case of singing, the music, in combination with the performer's skills, personality, and ability to create empathy will determine the success of artistic, political, or pedagogic communication. Second, the voice gives psychological clues to a person's self-image, perception of others, and emotional health. Self-image can be indicated by a tone of voice that is confident, pretentious, shy, aggressive, outgoing, or exuberant, to name only a few personality traits. Also the sound may give a clue to the facade or mask of that person, for example, a shy person hiding behind an overconfident front. How a speaker perceives the listener's receptiveness, interest, or sympathy in any given conversation can drastically alter the tone of presentation, by encouraging or discouraging the speaker. Emotional health is evidenced in the voice by free and melodic sounds of the happy, by constricted and harsh sound of the angry, and by dull and lethargic qualities of the depressed.  

Question: According to the passage, what does a constricted and harsh voice indicate?           

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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: What topic is this passage primarily concerned?         

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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: The word “sophisticated” in line 12 could best be replaced by?  

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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: What is the author’s main purpose in this 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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: Which of the following words is most similar to the meaning of “rustic”?            

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 following question from 44 to 50:

 The rules of etiquette in American restaurants depend upon a number of factors the physical location of the restaurant, e.g., rural or urban; the type of restaurant, e.g., informal or formal; and certain standards that are more universal. In other words, some standards 5 of etiquette vary significantly while other standards apply almost anywhere. Learning the proper etiquette in a particular type of restaurant in a particular area may sometimes require instruction, but more commonly it simply requires sensitivity and experience. For example, while it is acceptable to read a magazine in a coffee shop, it is 10 inappropriate to do the same in a more luxurious setting. And, if you are eating in a very rustic setting it may be fine to tuck your napkin into your shirt, but if you are in a sophisticated urban restaurant this behavior would demonstrate a lack of manners. It is safe to say, however, that in virtually every restaurant it is unacceptable 15 to indiscriminately throw your food on the floor. The conclusion we can most likely draw from the above is that while the types and locations of restaurants determine etiquette appropriate to them, some rules apply to all restaurants.  

 Question: Which of the following is closest in meaning to the word “tuck” in line 11?