Question

【题目】We were reading the newspaper _______ suddenly the light went out (熄灭).
A.when
B.while
C.as
D./

Answer 1

【答案】A
【解析】句意：我们正在看报纸，这时灯突然熄灭了。while当……时候； as当……时候；when引导的时间状语从句可表示动作突然发生，意为“这时”。句式：be doing when...,while 和as没有这种用法。故选when。