Question

【题目】You can save electricity by _______ the lights when you leave a room.

A. turn up B. turning on

C. turn off D. turning off

Answer 1

【答案】D

【解析】

试题分析：句意：你可以通过离开房间关灯来节约用电。A. turn up开大；B. turning on 打开； C. turn off 关上；D. turning off关上。依据句意，排除A,B；by为介词，后跟动词-ing形式。故答案为D。