求救OG中的一题解释

72. The number of undergraduate degrees in engineering awarded by colleges and universities in the United States
                    increased by more than twice from 1978 to 1985.

(A)  increased by more than twice

(B)   increased more than two times

(C)  more than doubled

(D)  was more than doubled

(E)   had more than doubled

OG对于A选项的解释引伸出的Twice用法疑问：

Choice A is faulty because an adverb such as twice cannot function as an object of the preposition by.

但是twice作为adv,可以有如下用法比如：

1）Twice three is six.

2）He has twice the strength he had.

3）M is twice as large as N.

这里面的twice难道是用作副词的么？副词怎么可能修饰名词或者数量词，甚或be怎么会接副词呢？

先谢谢您的解答了！

A by 后应跟名字或名词性短语

B more than 2 不符合original meaning

D E 时态不对