Section 16-III-16 19,Secrtion-15-5
Section15-IV-5
5. Only some strains of the tobacco plant are naturally resistant to tobacco mosaic virus, never becoming diseased even when infected. When resistant strains were experimentally infected with the virus, levels of naturally occurring salicylic acid in these plants increased fivefold: no such increase occurred in the nonresistant plants. In a second experiment, 50 nonresistant tobacco plants were exposed to tobacco mosaic virus, and 25 of them were injected with salicylic acid. None of these 25 plants showed signs of infection, however, the other 25 plants succumbed to the disease.
Which one of the following conclusions is most strongly supported by the results of the experiments?
(A) Tobacco plants that have become diseased by infection with tobacco mosaic virus can be cured by injecting them with salicylic acid.
(B) Producing salicylic acid is at least part of the mechanism by which some tobacco plants naturally resist the disease caused by tobacco mosaic virus.
(C) Salicylic acid is not produced in strains of tobacco plants that are not resistant to tobacco mosaic virus.
(D) It is possible to test an uninfected tobacco plant for resistance to tobacco mosaic virus by measuring the level of salicylic acid it contains.
(E) The production of salicylic acid in certain strains of tobacco plants can be increased and thus the strains made resistant to tobacco mosaic virus.
这题不是c), 是b),为啥？
Section16-III-19
Thomas: The club president had no right to disallow Jeffrey's vote. Club rules say that only members in good standing may vote. You've admitted that club rules also say that all members whose dues are fully paid are members in good standing. And since, as the records indicate, Jeffrey has always paid his dues on time, clearly the president acted in violation of club rules.
Althea: By that reasoning my two-year-old niece can legally vote in next month's national election since she is a citizen of this country, and only citizens can legally vote in national elections.The reasoning in Thomas' argument is flawed because his argument
(A) fails to take into account the distinction between something not being prohibited and its being authorized
(B) offers evidence that casts doubt on the character of the club president and thereby ignores the question of voting eligibility
(C) wrongly assumes that if a statement is not actually denied by someone, that statement must be regarded as true
(D) does not specify the issue with respect to which the disputed vote was cast
(E) overlooks the possibility that Althea is not an authority on the club's rules
能解释为什么是a)吗？
Section 16-III-16
Dr. Godfrey: Now that high school students are allowed to work more than 15 hours per week at part-time jobs, those who actually do so show less interest in school and get lower grades thin those who do not work as many hours at part-time jobs. Obviously, working long hours at part-time jobs during the school year contributes to the academic problems that many of our high school students experience.
Dr. Nash: That's not so. Many of our high school students set out to earn as much money as they can simply to compensate for their lack of academic success.15. Dr. Nash responds to Dr. Godfrey's argument by doing which one of the following? 16. The answer to which one of the following would be the most helpful in determining whether the conclusion that Dr. Godfrey draws could be logically defended against Dr. Nash's counterargument?
(A) whether people who have had academic problems in high school are ultimately less successful in their careers than people who have not had such problems
(B) whether students are allowed to spend more than 15 hours per week at school-sponsored nonacademic extracurricular activities such as team sports or clubs
(C) whether the students who work more than 15 hours per week and have academic problems had such problems before they began to work that many hours
(D) whether employers and high school students typically obey all the laws that regulate the conditions under which young people may legally be employed
(E) whether high school students who have after-school jobs continue to work at those jobs after graduating from high school
这题的解题思路把握不准，觉得每个选项都没有正确的长像。
谢谢!
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