扫描二维码，直接登录
题库 / Prep2007E1-SC-35
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.
which is a substance that promotes blood clotting, but not seriously interfering
a substance that promotes blood clotting, but not seriously interfering
a substance that promotes blood clotting, but does not seriously interfere
which is a substance to promote blood clotting, but does not seriously interfere
which is a substance that promotes blood clotting, but not a serious interference
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
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)
登录 或 注册 后可以参加讨论