请教 LSAT-22-3-21,LSAT-22-3-22,LSAT-22-3-23

SECTION22 3

21.   （假设）Even the earliest known species of land animals, known from fossils dating from the late Silurian period, 400 million years ago, show highly evolved adaptations to life on land. Since neither aquatic nor amphibious animals exhibit these adaptations, early species of land animals must have evolved very rapidly after leaving an aquatic environment.

Which one of the following is an assumption on which the argument depends?

(A) Known fossils of early land animals include fossils of animals that lived relatively soon after the first emergence of land animals.

(B) Fossils from the late Silurian period represent only a small number of the animal species that were alive at that time.

(C) No plants were established on land before the late Silurian period.

(D) No present-day species of aquatic animal is descended from a species of animal that once lived on land.（A）

(E) All animals alive in the late Silurian period lived either exclusively on land or exclusively in the water.

是否想在earliest known species与early species进行断桥连接,不知该题该如何分析

22.   On Saturday Melvin suggested that Jerome take the following week off from work and accompany him on a trip to the mountains. Jerome refused, claiming that he could not afford the cost of the trip added to the wages he would forfeit by taking off without notice. It is clear, however, that cost cannot be the real reason （直接取非反驳）for Jerome’s unwillingness to go with Melvin to the Mountains since he makes the same excuse every time Melvin asks him to take an unscheduled vacation regardless of where Melvin proposes to go.（简单思路）

The reasoning is most vulnerable to which one of the following criticisms?

(A) It attempts to forestall an attack on Melvin’s behavior by focusing attention on the behavior of Jerome.

(B) It fails to establish that Melvin could no more afford to take an unscheduled vacation trip to the mountains than could Jerome.

(C) It overlooks the possibility that Jerome, unlike Melvin, prefers vacations that have been planned far in advance.

(D) It assumes that if Jerome’s professed reason is not his only reason, then it cannot be a real reason for Jerome at all.（E）

(E) It does not examine the possibility that Jerome’s behavior is adequately explained by the reason the gives for it.

看了原来的帖子不明白(C)为什么不行呢?

23.   Arnold: I was recently denied a seat on an airline flight for which I had a confirmed reservation, because the airline had overbooked the flight. Since I was forced to fly on the next available flight, which did not depart until two hours later, I missed an important business meeting. Even though the flight on which I had a reservation was canceled at the last minute due to bad weather, the airline should still pay me compensation for denying me a seat on the flight.

Jamie: The airline is not morally obligated to pay you any compensation. Even if you had not been denied a seat on the earlier flight, you would have missed your business meeting anyway.

A principle that, if established, justifies Jamie’s response to Arnold is that an airline is morally obligated to compensate a passenger who has been denied a seat on a flight for which the passenger has confirmed reservations

(A) if the only reason the passenger is forced to take a later flight is that the airline overbooked the original flight

(B) only if there is a reason the passenger is forced to take a later flight other than the original flight’s being canceled due to bad weather

(C) only if the passenger would not have been forced to take a later flight had the airline not overbooked the original flight

(D) even if the only reason the passenger is forced to take a later flight were that the original flight is canceled due to bad weather（C）

(E) even if the passenger would still have been forced to take a later flight had the airline not overbooked the original flight

这道题我完全没有思路请朋友们指点.

因为我平时上网不太方便,所以一次问得多些,请原谅.

21.  Try deny test.  Deny the choice, and see whether the original conclusion will fall apart.  If so, then the choice is a necessary assumption.  Deny test will clearly indicate A is an assumption.

22. C introduces J's preferences, which is never discussed or hinted in the passage.  Therefore, C is a little bit out of scope.  Considering E directly attacks the main weakness of the argument, E is a better answer.

23.  It's actually asking for an assumption needed by Jamie.  J is basically saying "If aireline's overbooking is the ONLY reason for you to miss the meeting, then they are obliged to compensate.  Otherwise, they are not."  C essentially paraphrase this.