请教prep 07 1-35

udingzh

35.       (26325-!-item-!-188;#058&002592)

  In laboratory rats, a low dose of aspirin usually suffices to block production of thromboxane, which is a substance that promotes blood clotting, but not seriously interfering with the production of prostacyclin, which prevents clotting.

(A) which is a substance that promotes blood clotting, but not seriously interfering

(B) a substance that promotes blood clotting, but not seriously interfering

(C) a substance that promotes blood clotting, but does not seriously interfere

(D) which is a substance to promote blood clotting, but does not seriously interfere

(E) which is a substance that promotes blood clotting, but not a serious interference

answer is C

想请教一下为什么D不对，有NN说是因为D中的to do表目的，改变了原句的意思，但还是不太理解。

是不是因为D和C的逻辑论元不同，一个是promote, 另一个则是substance.

容绮

这里附上Manhattan Prep的Ron大神的解释，希望对楼主有帮助^^
"there are two problems i see in (d).
problem #1
a substance to promote... is unidiomatic.
the only context in which i can remember "a NOUN to VERB" is a context in which the NOUN is abstract in nature. for instance:
a way to produce goods
a reason to try harder
etc.
note that "substance" is a concrete item; it's not an abstraction like "way" or "reason".

if you're talking about concrete objects, you should replace the infinitive with something else. for instance:
* a substance to promote X (incorrect) --> a substance that promotes X (correct)
* a tool to install the shelves (incorrect) --> a tool with which to install the shelves (correct)

problem #2
"which is" is unnecessary and ugly.

if "which is" is followed by a description of something, you should just omit it, producing an appositive modifier:
X, which is a substance... (ugly) --> X, a substance... (better)
Person X, who is the coach of Team Y (ugly) --> Person X, the coach of Team Y (better)

udingzh

谢谢楼上