— do you have Art class?
— About once a week.
| A．How far | B．How long |
| C．How often | D．When |
I always go skiing with my friends ______ winter.
| A．in | B．on | C．at | D．for |
The students are talking about ______ holiday plans happily.
| A．his | B．her | C．its | D．their |
--Would you please tell me __________________?
-- At 10:00 this evening.
A. when will the train leave
B. when the train will leave
C. when does the train leave
Last month a new law _______in China to stop people from smoking in public places.
A. is passed B. passes C. was passed
Usually, we don`t know how important something is _____ we lose it.
A. or B. until C. as soon as