lsat-9-4-11

Dennies

A distemper virus has caused two-thirds of the seal population in the North Sea to die since May 1988. The explanation for the deaths cannot rest here, however. There must be a reason the normally latent virus could prevail so suddenly: clearly the severe pollution of the North Sea waters must have weakened the immune system of the seals so that they could no longer withstand the virus.

11.   Which one of the following, if true, most strongly supports the explanation given in the argument?

(A) At various times during the last ten years, several species of shellfish and seabirds in the North Sea have experienced unprecedented steep drops in population.

(B) By reducing pollution at its source, Northern Europe and Scandinavia have been taking the lead in preventing pollution from reaching the waters of the North Sea.

(C) For many years, fish for human consumption have been taken from the waters of the North Sea.

(D) There are two species of seal found throughout the North Sea area, the common seal and the gray seal.（A）

(E) The distemper caused by the virus was a disease that was new to the population of North Sea seals in May 1988, and so the seals’ immune systems were unprepared to counter it.

FRIENDS:HOW should i deal with this question?

robertchu

Use "process of elimination": eliminate choices B, C, D, E.

A is the best choice because if A is true, it can be established that the steep population drop is not limited to one specie, therefore something bigger than one type of virus, such as severe pollution, could be at play.

hedonism555

line of reasoning:

water contamination-->weaken immune system--> declined ability to withstand the latent virus--> death

if not water contamination, then virus will still remain latent.

A, other animals that have not latent virus but share the same water territory experienced the same decline. then, it is the water quality that causes the death.

[此贴子已经被作者于2005-1-31 1:54:29编辑过]