Q34: PP-SC45

Hydrocarbons, with which fruit flies perfume themselves in species-specific blends, are known to be important in courtship, and apparently this assists flies that taste the hydrocarbons on prospective mates to distinguish their own species from that of others.

A.      and apparently this assists flies that taste the hydrocarbons on prospective mates to distinguish their own species from that of

B.      and apparently this assists flies when they taste the hydrocarbons on prospective mates in distinguishing their own species from those of

C.      which apparently assists flies that tastes the hydrocarbons on prospective mates in being able to distinguish their own species from

D.      apparently assisting flies to taste the hydrocarbons on prospective mates to distinguish their own species from those of

E.       apparently assisting flies that taste the hydrocarbons on prospective mates in distinguishing their own species from

D E到底怎么区分哦？thx

assist (sb)in doing排除D的assisting flies to... /D中的those无指代

E assisting flies.....in distinguishing ...

很不幸的也选了E。

Google了一下找到了原句：http://www.nytimes.com/2000/10/24/science/24SPEC.html?pagewanted=2

同意我们的遵循assist sb. in doing sth的惯用用法。但是X's species为什么可以直接和Y比而不是跟Y's species比呢？