They kept trying ________ they must have known it was hopeless.
A: If
B: because
C: when
D: where
A: If
B: because
C: when
D: where
举一反三
- They kept trying _____ they must have known it was hopeless.
- Where to find the teacher and where to do the experiment ______. A: are not known B: is not known C: has not known D: have not known
- In order to use the normal distribution for interval estimation of m when s is known, the population A: must be very large B: must have a normal distribution C: can have any distribution D: must have a mean of at least 1
- Sorry, I’m late. I ____________you waiting. A: should not keep B: should not have kept C: should have kept D: must not have kept
- Little ______ when I took the trip where it would lead me. A: have I known B: had I known C: do I know D: did I know