It is his cleverness, not his strenth, ____ defeated his rival.
| A．that | B．which | C．what | D．who |
To protect the environment, the local government has put up a lot of ______ to warn the citizens not to litter the ground.
| A．sighs | B．sights | C．signals | D．signs |
Corruption is _______ problem in countries across the world, with developing countries often believed to be more serious, although there is no evidence to suggest this is _______case.
| A．a; the | B．the; a | C．不填; the | D．a; a |
— How much influence will your time in high school have on the rest of your life?
— It ______ be quite a lot, or perhaps only a little.
| A．might | B．must | C．should | D．can |
If Peter had not hurt his leg, he ______ the important meeting last week.
| A．will attend | B．attended |
| C．would have attended | D．would attend |
______ yourself, you should never put convenience before safety.
| A．Protecting | B．Having protected | C．Protect | D．To protect |