Migraine, the most debilitating common form of headache, afflicts perhaps 18 million Americans, who collectively lose 64 million workdays a year, and they cost the nation $50 billion in medical expenses and lost work time. B

(A) year, and they cost the nation $50 billion in medical expenses and lost

(B) year and thus cost the nation $50 billion in medical expenses and lost

(C) year, so as to cost the nation $50 billion in medical expenses and lost

(D) year that costs the nation $50 billion in lost medical expenses and（B）

(E) year, which thus cost the nation $50 billion in lost medical expenses and

看了以前的帖子 似乎也没个结果 翻出来 在讨论一下 我选C

cost 的主语 不能是人阿~~

那位强人帮我找找C的毛病... 感谢感谢...

如果句子是这样的，也就是C选项：Migraine, the most debilitating common form of headache, afflicts perhaps 18 million Americans, who collectively lose 64 million workdays a year, so as to cost the nation $50 billion in medical expenses and lost work time. 这样的句子肯定是不对的。因为：cost的逻辑主语肯定还是Migraine，即我们可以把划线的部分去掉。那么就成了Migraine, the most debilitating common form of headache, afflicts perhaps 18 million Americans so as to cost the nation $50 billion in medical expenses and lost work time. 问题就出来了，你查查原版词典就知道，so as to do sth的意思是：为了做... ...，它的色彩是很主观的。可是，很明显migraine不可能有任何主观意愿，这种结果是顺其自然的，并非其目的。

所以，C选项不对。

我觉得Americans可以作为cost的主语

就是这些患有偏头疼的美国人使得美国付出了...的代价