Question

It was a long time before the police________what he was really doing.

1. A.
   caught hold of
2. B.
   caught up
3. C.
   caught on to
4. D.
   caught at

Answer 1

C
试题分析：句意：还要过一段时间警察才能了解他在做什么。catch hold of抓住； catch up 赶上； catch on to理解； catch at试图抓住。根据句意故选C。
考点：考查动词短语的用法。
点评：本题难度适中。对于动词短语的考查常考同源介词或同源副词的动词短语，需要考生熟记它们的意义和用法，以提高解题的正确率。这里是考查含有catch的短语。
即学即练：I threw the rope and he _______it.
A. caught hold of    B. caught up     C. caught on to      D. catch at
解析：A。句意：我把绳子扔了过去，他一把就抓住了。