He realized she was crying ________ what he had said.
| A．because | B．becauseof | C．as | D．since |
Lacking _______ evidence, the police couldn’t arrest the man.
| A．ordinary | B．potential |
| C．solid | D．common |
A kind passenger paid for my ticket, without which I _______ the last train.
| A．couldn’t catch | B．couldn’t have caught |
| C．didn’t catch | D．hadn’t caught |
—I have done well in the exam because of no careless mistakes.
—Congratulations! Students can never be _______ careful in exams.
| A．so | B．very | C．too | D．enough |
With so many good friends together with you, you must have been happy during the past National Golden Week, _____?
| A．haven’t you | B．didn't you |
| C．weren’t you | D．mustn’t you |
There are more than 740 million Chinese _______ to second-hand smoking in public places now.
| A．are being exposed | B．exposed |
| C．to expose | D．having been exposed |