947-409 一个比较奇怪的题

iselibra

409.    In the last ten years, the dropout rate among Black high school students fell substantially over the past decade, while the number of Blacks who attend college is more than twice what it was.
(A) fell substantially over the past decade, while the number of Blacks who attend college is more than twice what it was
(B) fell substantially, while the number of Blacks attending college is more than double what it was at that time
(C) has fallen substantially, while the number of Blacks attending college has more than doubled
(D) has fallen substantially over the past decade, while the number of Blacks attending college is more than twice what it was at that time
(E) has fallen substantially over the past decade, while the number of Blacks who are attending college are more than double what they were
答案是C，可是C连past decade也没有了？
这能对么？

深海的小美人鱼

前面不是说了In the last ten years吗、 为什么还要重复呢

iselibra

不好意思....
粗心了