--- Did you turn off the lights before you left the puter room?
---- Oh, I forget them off. I’ll go to do it.
A. to turn
B. having been turned
C. to have turned
D. turning
网友回答
(答案→)A. to turn
B. having been turned
C. to have turned
D. turning
解析：考查forget的用法。“你离开电脑室前关灯了吗？”“噢，我忘记关了。我现在就去关。”forget to do sth.“忘记要做某事”；forget doing sth.“忘记做过某事”。根据答语可知，没有做关灯这个动作，故加不定式，排除B、D；A项表示未做。故选A。