Question

一道英语选择题···原因

There is____abundant evidence that cars have____harmful effect on the environment.
A.an;a B.an;/ c./,a D./;/

Answer 1

C
evidence作"证据；根据"讲时为不可数名词，故前不用冠词。
have an effect on对~~~有影响
由于harmful为辅音音素开头的单词，故前的冠词用a.

Answer 2

C.
evidence 不可数，所以什么都不加。
have a harmful effect on 对…有害