____ anyone phone during the board meeting, please tell them I am busy.
| A．Should | B．Will | C．May | D．Can |
The parents are _____ their son who has been away from home for days.
| A．in search of | B．to search |
| C．searching | D．searched for |
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 |