旧prep语法笔记第35题~

左摇右摆

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  
请问C项和D项：C项中but does not seriously interfere可以跳过同位语substance 与主句谓语动词suffices平行，句 子结构为a low dose of aspirin suffices ...,but does not interfere...
那D项中的 but not a serious interference  不能跳过which引导的定语从句与主句谓语动词suffices平行吗？
答案选择的是C

michaelyueyue

说得对，同位语优先
这题秒杀步骤，先考虑同位语从句 BC中选，
再考虑but的平行，选c

个人认为楼上几位说的有偏差，d的which就是定production of thromboxane的，没有错
错在but如果按d这种用法就变成介词除了，而在这里but应该是连词“但是”的意思，所以毫无疑问排除d

bennywang2usa

不是的，童鞋。

这个句子是同位语啊。比如我们说句子主干是主谓宾（SVO）。那么型如S,...,VO的结构，其中的...就是同位语。而同位语必须是“名词性的”。which显然引导了一个句子。所以是错的。而且GMAT的语法倾向于使用同位语结构说明所修饰的部分。

左摇右摆

能再解释的清楚一些吗？是不是说D项没有C项简洁？

judydongxueni

前面有逗号啊，就不用加which啦