----_______ do you brush your teeth?
----- Twice a day.
A .How much B. How often C. How long
When she passed the room, the nurse noticed the old lady _______ to get out of bed.
| A．tried | B．trying | C．to try | D．tries |
Last week we went camping and we _______ a tent near a lake .
| A．put up | B．put on |
| C．put in | D．put down |
The young men walked _______ the forest(森林) and came to a big river at last.
| A．on | B．over | C．through | D．across |
________ a warm, sunny day, Alice got tired of having nothing to do.
| A．On | B．In | C．At | D．To |
—Who helped you with your homework?
— _______ . I did it myself.
| A．Somebody | B．Everybody | C．Nobody | D．Anybody |