Question

--- 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

Answer 1

D

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。