—Are you sure ______ you've met him before
A: unless
B: that
C: when
D: though
A: unless
B: that
C: when
D: though
举一反三
- I don’t think you’ve heard of him before, ________?
- I don’t think you’ve heard of him before, ________? A: have you B: haven’t you C: do I D: don’t you
- ____________ you are sure there are no gas leaks, don't light any matches. A: If B: When C: As D: Unless
- It's six weeks ______ I met you last. A: when B: since C: before D: for
- I don't think you've heard of him before,_____? A: don't I B: do I C: have you D: haven't you