Last year the number of students who graduated with a driving license reached 200,000, a(n) ________ of 40,000 per year.
| A．amount of | B．quantity |
| C．average | D．number |
In Britain,sales of cigarettes have been reduced __________ 30% in the past ten years.
| A．for | B．to | C．from | D．by |
Whenever you are to walk on the ice,__________ that it is solid and safe enough.
| A．examine | B．check | C．try | D．make |
It is a __________ that you missed such a wonderful concert.
| A．shame | B．pity | C．regret | D．mistake |
Because of the snow,many parts of the countryside are only _________ by helicopter.
| A．available | B．appropriate | C．accessible | D．achievable |
I tried hard to get some information about the new technology out of his mouth,but he remained __________.
| A．quiet | B．secret | C．silent | D．calm |