How this kind of plant can be ____ in a special way is still unknown to us.
| A．kept away | B．kept out | C．kept alive | D．kept off |
When the meeting was ______, it was already midnight.
| A．at the end | B．end up | C．at an end | D．in the end |
– I’m leaving for Beijing next week.
– How long ______ there?
| A．have you stayed | B．are you staying | C．had you stayed | D．did you stay |
______ he has made up his mind, no one can make him change it.
| A．Once | B．Unless | C．Until | D．As |
I ______ him to give up smoking, and succeeded.
| A．persuaded | B．tried to advise | C．tried to persuade | D．suggested |
This is the first time that I ______ the song Gangnam Style.
| A．hear | B．are hearing | C．heard | D．have heard |