As a rule, you can borrow only two books ______ in the library.
| A．at one time | B．at a time | C．in no time | D．at times |
_______, I’d have told you.
| A． If I would have known | B． If I had have known |
| C． Had I known | D． Should I know |
20. He reads newspapers every day to keep himself_______about what's going on in the world.
| A．inform | B．informing | C．informed | D．being informed |
We_______such great progress without your efforts. Thanks a lot.
| A．shouldn’t have made | B．couldn’t have made |
| C．were unable to make | D．mustn’t have made |
Our success was largel_______the good cooperation of all team members.
| A．because | B．result from | C．due to | D．thanks to |
For a long time they walked without saying _________ word. Mike was the first to break __________ silence.
| A．the; a | B．a; the | C．a; / | D．the; / |