We were about to go out the rain poured down. A. asB. whileC. afterD. when

问题补充：

We were about to go out the rain poured down.

A. as

B. while

C. after

D. when

答案：

A. as

B. while

C. after

(答案→)D. when

解析：考查固定句式。固定句式：be about to do sth when…正在做某事在这时…；这里的when是一个并列结构。句意：我们正要外出，在这时大雨倾盆而下。故D正确。