You’d better ________ some money for special use. [ ]

We were about to climb up to the top of the mountain ________ it began to rain heavily.

s car broke down on the way home and when he finally got home, he found he had left his key in the office.– _______________.

I can’t find Mary. Where’s she —Sorry, I don’t know ______.

He can’t state clearly how long he has___________ the bicycle