问题补充：
The key word in the sentence has been , so it doesn make any sense to us.
A. picked up
B. held up
C. left out
D. made out
答案：
A. picked up
B. held up
(答案→)C. left out
D. made out
解析：短语辨析。A捡起，无意中学会，接受，康复；B阻碍，延误；C遗漏；D理解，辨认；结合句意可知C正确。句意：这个句子的关键词被遗漏了，所以对我们来说这个句子讲不通。
