Every possible means ______ to prevent the air pollution, but the sky is still not clear.
| A．has been used | B．have been used |
| C．is used | D．are used |
He will come to understand your efforts sooner or later. It's just a matter of.
| A． | luck | B． | value | C． | time | D． | fact |
This training program can give you a lift at work,increase your income by 40%.
| A． | as well as | B． | so long as | C． | so much as | D． | as soon as |
In our class there are 46 students,half wear glasses.
| A． | in whom | B． | in them | C． | of whom | D． | of them |
Before driving into the city, you are required to get your car.
| A． | washed | B． | wash | C． | washing | D． | to wash |
They are living with their parents for the moment because their own house ____.
| A．is being rebuilt | B．has been rebuilt | C．is rebuilt | D．has rebuilt |