Question

Yesterday morning I was just leaving_______ the telephone rang.

A．when

B．while

C．because

D．since

Answer 1

A

试题分析：句意：昨天早上我正要离开时电话铃响了。When当…时；while当……时； because 因为；since自从。表示某事正在进行时发生了另一件事，常用when，所以选A。