问题
选择题
—Do you know _____ Tom's sister is a doctor or not?
—No, I don't know. [ ]
A. that
B. whether
C. where
D. what
答案
答案:B
—Do you know _____ Tom's sister is a doctor or not?
—No, I don't know. [ ]
A. that
B. whether
C. where
D. what
答案:B