I don't know _____ they have passed the exam or notA.where B.if C_英语解答

I don't know _____ they have passed the exam or not
A.where B.if C.whether D.when

人气：143 ℃　时间：2019-08-19 04:17:12

解答

选C
whether...or not
I don't know 【whether】 they have passed the exam or not
我不知道他们有没有通过考试.