Question

He was about half through his meal ______ a familiar voice came to his ears.

A．why

B．where

C．when

D．while

Answer 1

C

试题分析：考查when引导的时间状语从句，when可以表示“当…时候”，也可以表示 “这时”，相当于at that time，句意：他刚吃完一半的饭这时听到一个熟悉的声音。选C。
点评：when引导时间状语从句时表示“当……的时候”， when既可以指时间段也可指时间点， 从句中既可用延续性动词又可用非延续性动词， 且动作既可和主句的动作同时发生又可在主句的动作之前或之后发生，when也可以表示 “这时”，相当于at that time，适用于：be about to do… when…,be doing…when…,had done…when…。