Although the police thought he was the most likely one, _____ they had no exact proof about it, they could not arrest him.
| A．when | B．until | C．before | D．since |
The fire spread through the hotel very quickly, but everyone __________ get out.
| A．had to | B．would | C．could | D．was able to |
---Can I help you, sir?
---Yes. I bought this radio here yesterday, but it _____.
| A．didn't work | B．wouldn't work | C．can't work | D．doesn't work |
The Internet has brought _____ big changes in the way we work．
| A．about | B．out | C．back | D．up |
It was dark. We decided to ______for the night at a farmhouse.
| A．put away | B．put down | C．put up | D．put on |
—Do you think she’s going to leave?
—The ______had crossed my mind.
| A．matter | B．hope | C．desire | D．thought |