--- Look! Lots of people there. What’s wrong?
--- An old lady was going across the road a car hit her.
A. while
B. as
C. whether
D. when
网友回答
A. while
B. as
C. whether
(答案→)D. when
解析：连词辨析。在表示时间时，while强调动作同时发生。As强调伴随动作，when当……时。Whether的意思是是否。句意：看，那儿有许多人，怎么了？——一位老太太正在过马路，突然一辆汽车撞到了她。“ be doing…when…是一个句型，多译为某人正在做……时，突然……。故选D。