Question

Susan _______out _______the door opened and in came three strangers.

[　　]

A．was just to go; while

B．just went; as

C．was just going; as soon as

D．was just about to go; when

Answer 1

答案：
解析：

be about to do sth. when是一个固定的句型，表示正要做某事的时候突然发生另外一件事。when此处相当于并列连词，意为“on the point of doing sth.”,“be going to do sth.”等。