问题 选择题

I ________ work out the problem at first, but after my teacher showed me an example, I ________ get the answer easily.

A.couldn’t; was able to

B.can’t; could

C.wasn’t able to; could

D.was able to; was able to

答案

答案:A

题目分析:句意:起初我不能做出那个问题,但是在老师给我做了例子后,我就很容易地得到了答案。can作情态动词的基本意思是“能,能够”“可以”“可能,会”,可表示体力、智力能够完成一件事情或环境赋予的能力; 也可表示由于环境或其他因素而产生的可能性,只有现在时和过去时两种形式,,它可表示不一定能够做完一件事;而be able to则有多种时态形式。有能力做,并且做完了事情。故选A。

点评:本题难度适中。情态动词是近几年高考的热点,本题在于考查考生be able to 和can /could的区别及不同的用法的掌握情况。

即学即练:The fire spread through the hotel very quickly but everyone _______ get out.

A. had to              B. would            C. could                D. was able to

解析:D。句意:表示过去具体某次“能够”做成某事只能用 was / were able to 而不用could。

综合
单项选择题