I was about to go to bed one of my old classmates made a call to me.A. whenB. asC. whileD

问题补充：

I was about to go to bed one of my old classmates made a call to me.

A. when

B. as

C. while

D. that

答案：

(答案→)A. when

B. as

C. while

D. that

解析：句型考查。Be about to do sth when… 刚要…这时…。句意：我刚要睡觉这时一位老同学打电话给我。