题目内容
— Why do you do volunteer work in the North-West?
— I_______ to improve the lives of the children there through my efforts.
| A．was trying | B．have tried | C．am trying | D．tried |
C
解析试题分析：考查时态。句意：--你为什么选择去西北地区做志愿服务？--通过我的努力，我正在努力改善那里孩子们的生活。过去进行时用来指过去的某个时刻正在发生的事情，根据第一句中的Why do you...可知，这里不用过去的时态，排除A、D；现在完成时表示发生在过去的事情对现在造成的结果，参加志愿服务这件事并未结束，因此不用现在完成时，故选C。
考点：考查时态
同步练习强化拓展系列答案The girl _______ in bed _______ to us that she had _______ the dictionary on the bookshelf.
| A．lay; lied; lay | B．lying; lied; laid | C．lying; lay; laid | D．lied; lied; laid |
We arranged to meet at 8:00 , but she never__________.
| A．turned up | B．turned down | C．turned off | D．turned over |
Mary did do some bad things about me, but I have ______ her for that.
| A．regretted | B．freed | C．relaxed | D．forgiven |
He was a bit nervous. He _________his spare breath with a soft sound that was almost heard by the audience.
| A．gave out | B．let out | C．picked out | D．blew out. |
Mr. Brown’s condition looks very serious and it is doubtful if he will ________.
| A．pull back | B．pull up | C．pull through | D．pull out |
It is reported that a foreign company will _______ the company.
| A．think over | B．turn over | C．hand over | D．take over |
As a leading producer of greenhouse gases, China the United States as the largest consumers of energy．
| A．describes | B．joins | C．controls | D．influences |
—Sorry, I didn't catch you.
—Be quiet, please; the baby ________.
| A．was sleeping | B．is sleeping |
| C．slept | D．has slept |