885,20,9

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.

(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

还是觉得B 不对, cost应该是指Migraine. 前人的解释不太合适阿

11.   Sales of United States manufactured goods to nonindustrialized countries rose to $167 billion in 1992, which is 14 percent more than the previous year and largely offsets weak demand from Europe and Japan.

(A) which is 14 percent more than the previous year

(B) which is 14 percent higher than it was the previous year

(C) 14 percent higher than the previous year’s figure

(D) an amount that is 14 percent more than the previous year was（E）

(E) an amount that is 14 percent higher than the previous year’s figure

an amount 能higher than 么?  rate差不多吧,

an amount 应该是大小多少

我选了D了.

Migraine　afflicts perhaps 18 million Americans, who collectively lose 64 million workdays a year and thus cost the nation $50 billion in medical expenses and lost work time.

答：Americans thus cost the nation $50 billion in medical expenses and lostwork time.

哦　明白了～～

1,这些人花费了国家n多的钱是可以的。

2，D, amount    和 the previous year 相比。