_______ on time, this medicine will be quite effective.
| A．Taking | B．Being taken |
| C．Taken | D．Having taken |
-Mary, would you like to come to my birthday party? -_____.
| A．Of course, you could | B．Sure. Go ahead |
| C．Sorry, you may not | D．No, you mustn’t |
—Don’t press the button，John.
—What if I________？
| A．did | B．would | C．will | D．shall |
Li Yang, the founder of Crazy English, says that he copies it down _______ he comes to a sentence.
| A．unless | B．while | C．because | D．every, time |
Young people should learn how to_____some money for the future.
| A．hand out | B．make up | C．put away | D．get in |
Nine thousand guests took part in the outdoor ceremony,that impressed so many people at the White House．
| A．that | B．this | C．it | D．one |