Question

【题目】You’ll get a toothache ______ you clean your teeth regularly.

A.becauseB.whenC.ifD.unless

Answer 1

【答案】D

【解析】

句意：你会牙疼，除非你有规律的刷牙。

You’ll get a toothache和you clean your teeth regularly可知是除非；because因为，when当……时候，if如果，unless除非；故选D。