. --- The terrible accident is under investigation.
--- Actually, quicker action______ those workers trapped in the mine.
| A．might have saved | B．must have saved |
| C．should have saved | D．could have saved |
33. The little boy is very clever _____ every subject.
| A．at | B．in | C．about | D．On |
32. When the Chinese delegation arrived at Vienna airport, they were received _____ cheers.
| A．in | B．for | C．on | D．With |
31. Einstein didn’t care for money. Once he used a check _____ $1000 as a bookmark and then he lost it.
| A．for | B．of | C．about | D．To |
30. More than 20 years ago he was badly wounded in the anti-Vietnam war. Since then he can only walk _____ an arm-chair .
| A．in | B．on | C．by | D．Over |
29. Can you say _____ certain when he will come here?
| A．at | B．for | C．with | D．In |