Question

While __________ for the bus, I happened to come across my childhood friend, Tom. A．waited ..

While __________ for the bus, I happened to come across my childhood friend, Tom. A．waited B．wait C．waiting D．to wait

Answer 1

C

试题分析：考查状语从句的省略式，当主从句的主语一致时，要省略从句的主语和be动词，while waiting="while" I was waiting，句意：当我在等公共汽车的时候，碰巧遇到儿时的朋友，汤姆。选C。 点评：此类题目可以使用还原法做题，也可以当成非谓语动词做，考虑主语和动词的关系。