12. He gave us a nod and muttered a “yes” after _______ seemed like hours.
| A．that | B．which | C．it | D．What |
The book, _______ is blue, is mine.
| A．cover of which | B．which cover |
| C．of which the cover | D．all the above |
_____ the watch and see if you can find out what’s wrong with it.
| A．Pack up | B．Break down | C．Dig out | D．Take apart |
John is a good swimmer, but I don’t like the way ____ he always shows off in front of everyone.
| A．how | B．why | C．不填 | D．which |
_____ you understand the rules of the game, you will enjoy it.
| A．Before | B．Even if | C．Once | D．While |
The child asked his mother ______ go out to play tennis.
| A．that he could | B．if he could | C．if could he | D．that could he |