46. Twelve healthy volunteers with the Apo-A-IV-1 gene and twelve healthy volunteers who instead have the Apo-A-IV-2 gene each consumed a standard diet supplemented daily by a high-cholesterol food. A high level of cholesterol in the blood is associated with an increased risk of heart disease. After three weeks, the blood cholesterol levels of the subjects in the second group were unchanged, whereas the blood cholesterol levels of those with the Apo-A-IV-1 gene rose 20 percent.
Which one of the following is most strongly supported by the information above?
A.Approximately half the population carries a gene that lowers cholesterol levels.
B.Most of those at risk of heart disease may be able to reduce their risk by adopting a low-cholesterol diet.
C.The bodies of those who have the Apo-A-IV-2 gene excrete cholesterol when blood cholesterol reaches a certain level.
D.The presence of the Apo-A-IV-1 gene seems to indicate that a person has a lower risk of heart disease.
E.The presence of the Apo-A-IV-2 gene may inhibit the elevation of blood cholesterol.
E：正确，inhibit the elevation of blood cholesterol-----〉the blood cholesterol levels of the subjects in the second group were unchanged
47. High school students who feel that they are not succeeding in school often drop out before graduating and go to work. Last year, however, the city’s high school dropout rate was significantly lower than the previous year’s rate. This is encouraging evidence that the program instituted two years ago to improve the morale of high school students has begun to take effect to reduce dropouts.
Which one of the following, if true about the last year, most seriously weakens the argument?
A.There was a recession that caused a high level of unemployment in the city.
B.The morale of students who dropped out of high school had been low even before they reached high school.
C.As in the preceding year, more high school students remained in school than dropped out.
D.High schools in the city established placement offices to assist their graduates in obtaining employment.
E.The antidropout program was primarily aimed at improving students’ morale in those high schools with the highest dropout rates.
The passage puts forward a phenomenon that last year, however, the city’s high school dropout rate was significantly lower than the previous year’s rate; the passage attributes the phenomenon to the explanation that there is some program and the program helps the students’ morale. However if there are other reasons that could explain that mentioned phenomenon, the argument will be seriously weakened.
Choice A, by pointing out that a recession caused a high level of unemployment in the city, explains the phenomenon clearly. Furthermore, Choice A negates the effects of the so-called morale program. The students stay in the school not because they want to, but because they cannot find jobs so they have to stay.
Choice B has nothing to do with the reasoning in the passage because the passage does not deal with anything about the students before they join high school.
Choice C deals with the students remain in high school. However the passage discusses about students who dropped out.
Choice D clarifies what the program did about helping the students. This does not weaken the argument in the passage.
Choice E, just as D, only tells about the content of the program, does not weaken the argument.
看看这句话High school students who feel that they are not succeeding in school often drop out before graduating and go to work.这里是说学生是因为觉得不可能在学校取得成功才辍学找工作的。仅仅是帮助学生找工作不能解决学生的moral问题。因此D没有在根本上削弱。---- 深海的小美人鱼
因为学校成立了 placement offices 来帮助毕业生找工作，所以学生就不退学了
这句话的前提是学校帮不帮忙找工作决定学生退不退学，这在原文中并没有说明。如果单从学生不退学讲，这可以算作是支持。而原文的“drop out before graduating and go to work”的必然前提是学生可以go to work,也就是有地方可去，所以否定这个前提学生就不会退学，因此构成了“就业形势不好，学生就不退学了”这个他因。--- seanql
48. The television show Henry was not widely watched until it was scheduled for Tuesday evenings immediately after That’s Life, the most popular show on television. During the year after the move, Henry was consistently one of the ten most-watched shows on television. Since Henry’s recent move to Wednesday evenings, however, it has been watched by far fewer people. We must conclude that Henry was widely watched before the move to Wednesday evenings because it followed That’s Life and not because people especially liked it.
Which one of the following, if true, most strengthens the argument?
A.Henry has been on the air for three years, but That’s Life has been on the air for only two years.
B.The show that replaced Henry on Tuesdays has persistently had a low number of viewers in the Tuesday time slot.
C.The show that now follows That’s Life on Tuesdays has double the number of viewers it had before being moved.
D.After its recent move to Wednesday, Henry was aired at the same time as the second most popular show on television.
E.That’s Life was not widely watched during the first year it was aired.
Joseph: My encyclopedia says that the mathematician Pierre de Fermat died in 1665 without leaving behind any written proof for a theorem that he claimed nonetheless to have proved. Probably this alleged theorem simply cannot be proved, since---as the article points out---no one else has been able to prove it. Therefore it is likely that Fermat was either lying or else mistaken when he made his claim.
Laura: Your encyclopedia is out of date. Recently someone has in fact proved Fermat’s theorem. And since the theorem is provable, your claim---that Fermat was lying or mistaken---clearly is wrong.
49. Joseph’s statement that “this alleged theorem simply cannot be proved” plays which one of the following roles in his argument?
A.an assumption for which no support is offered
B.a subsidiary conclusion on which his argument’s main conclusion is based
C.a potential objection that his argument anticipates and attempts to answer before it is raised
D.the principle claim that his argument is structured to refute
E.background information that neither supports nor undermines his argument’s conclusion
EVIDENCE1：百科全书说：P宣称已证明某理论，但没有留下任何书面证据。(My encyclopedia says …….have proved.)
EVIDENCE2：没有人能够证明(since…. prove it)
50. Which one of the following most accurately describes a reasoning error in Laura’s argument?
A.It purports to establish its conclusion by making a claim that, if true, would actually contradict that conclusion.
B.It mistakenly assumes that the quality of a person’s character can legitimately be taken to guarantee the accuracy of the claims that person has made.
C.It mistakes something that is necessary for its conclusion to follow for something that ensures that the conclusion follows.
D.It uses the term “provable” without defining it.
E.It fails to distinguish between a true claim that has mistakenly between believed to be false and a false claim that has mistakenly been believed to be true.