.I was about to leave for work the telephone rang.A. asB. untilC. whileD. when

问题补充：

.I was about to leave for work the telephone rang.

A. as

B. until

C. while

D. when

答案：

A. as

B. until

C. while

(答案→)D. when

解析：考查固定搭配;be about to do …when….刚要做…这时….，句意是：我刚要去上班这时电话响了。选D。