Question

Virus can stay on our hands for long, so remember to wash your hands with some soap and water carefully ________ you come inside. It is the best way to fight novel coronavirus.

A.when B.before C.while D.and

Answer

A

【解析】

句意：病毒会在我们的手上停留很长时间，所以当你进来的时候记得用肥皂和水仔细洗手。这是对抗新型冠状病毒的最好方法。

考查连词辨析。When当……的时候；. Before在……之间；while当……的时候；and和，又。根据“so remember to wash your hands with some soap and water carefully”可知，此处是when引导的时间状语从句，用when来引导。根据题意，故选A。