大全补充146题

in the last century 是大段的时间概念，要用现在完成时-这个确定吗？

看了以前关于这道题的帖子 说是因为前面the recent election  导致过去延伸到现在而选择完成时的

不过

141 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 （C）

(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

也因为有个In the last ten years而选择了完成时

所以不解。。。

Sth./sb. Changed 被改变，

 sth./sb. Change, 改变。
                

In the last century表示过去的时间段

change : [intransitive and transitive]to become different, or to make something become different
Susan has changed a lot since I last saw her.

Changing your eating habits is the best way to lose weight.

The rules are not going to change overnight (=change quickly) .

Why do the leaves on trees change colour in the autumn?