LSAT-11-1-24【antibody test】

24. The body of anyone infected by virus X will, after a week, produce antibodies to fight the virus: the antibodies will increase in number for the next year or so. There is now a test that reliably indicates now many antibodies are present in a person’s body. If positive, this test can be used during the first year of infection to estimate to within a month how long that person has had the virus.

Which one of the following conclusions is best supported by the statements above?

(A) Antibodies increase in number only until they have defeated the virus.

(B) Without the test for antibodies, there is no way of establishing whether a person has virus X.

(C) Antibodies are produced only for viral infections that cannot be fought by any other body defenses.

(D) If a person remains infected by virus X indefinitely, there is no limit to the number of antibodies that can be present in the person’s body.

(E) Anyone infected by virus X will not a time fail to exhibit infection if tested by the antibody test

key's E.用排除法很容易选出来，但是不明白最后一句话“If positive, this test can be used during the first year of infection to estimate to within a month how long that person has had the virus.
”是用来估测在一个月内病人带有病毒的时间长短吗？这个estimate to within a month跟推出的答案没多大关系吧？

通过antibody数量估测带有virus的时间长短，E好像有点assumption的味道了。

1。如果呈阳性，可用这个实验去估计那个人感染病毒的时间，精确度可在一个月内

2。E对的原因：原文是after a week才产生produce antibodies ，而the antibody test是靠测antibodies来显示是否感染病毒。故有for a time (你的答案中not a time是错的)测不到感染

E：如果被test，被病毒感染的人在一段时间那不会显示出感染的迹象。

fail to exhibit infection，但是有可能已经produce antibody了呀。这样一来，test测出的还是不准确啊。

哎呀，想糊涂了。