She was about to leave the room the telephone rang.A. whenB. whileC. afterD. since

问题补充：

She was about to leave the room the telephone rang.

A. when

B. while

C. after

D. since

答案：

(答案→)A. when

B. while

C. after

D. since

解析：句意：当她正要离开房间时，电话铃响了。When当……时候 while在……期间 after在……以后since自从，根据题意，选A。