_____ the mountain is， _____ the air is．（ ）
A．The highest， the thinnest
B．Higher， thinner
C．The higher， the thinner
______ do teenagers need to sleep ？
At least eight hours a night．（ ）
| A． |
How long |
B． |
How many |
C． |
How often |
Why are you worried？
The movie will start in 20 minutes ， but the bus______ hasn't come．（ ）
| A． |
still |
B． |
already |
C． |
always |
What else do we need to make cold beef ？
_________．（ ）
| A． |
Two spoons salt |
B． |
Two spoons of salts |
C． |
Two spoons of salt |
What _____ will you win after winning the competition in the program Stay to the End（一站到底）？
A free trip to Bali Island．（ ）
| A． |
prize |
B． |
attention |
C． |
advice |
Excuse me， sir． Is the swimming pool open all day？
_____． Only from 6：30 p．m． to 9：30 p．m．（ ）
| A． |
That's right |
B． |
Yes，of course |
| C． |
Sorry，I'm afraid not |
D． |