To keep the air fresh during the night, I often sleep wi Wap版

试题详情及答案解析

To keep the air fresh during the night, I often sleep with the windows on ________ it’s really cold.

A．unless

B．if

C．because

D．when

答案：A

试题分析：句意:为了夜里睡觉空气新鲜，我经常开着窗子睡觉，除非天气很冷。unless除非……否则……，引导条件状语从句，符合语境；if如果；because因为；when当……时候。三者都不合语境，故选A
考点：考查连词。