I think that's unlikely to happen, but if that ______ occur, both America's and China's interest would be severely damaged.
I can meet you at eight o'clock or __________ you can pick me up.
You can always rely on __________ Jack says, as he never tells a lie.
-The car comes to a sudden stop. What's wrong?-The oil has __________.
It isn't quite __________ whether the teacher will collect the homework by Friday, so you needn't hurry.
I found the homework was not so heavy as __________ I __________ to get in my old school.