I don't know ____ they have passed the exam.A.what B.if C.when D._英语解答

I don't know ____ they have passed the exam.A.what B.if C.when D.where谢谢了,

人气：192 ℃　时间：2019-08-22 00:14:52

解答

选B.考查宾语从句的用法,根据语意“是否”,因此只能用if或whether.