Our country is taking action to ______ air pollution．（ ）
A．cut downB．cut upC．cut outD．cut off
Anna is preparing for the coming exam， so she has to ____ the invitation to the party．（ ）
A．turn onB．turn downC．turn offD．turn up
____ have you talked with your friends on the phone？
Since I finished my homework．（ ）
A．How farB．How oftenC．How soonD．How long
Oh， dear! I can't find my key to the office．
Don't worry． I think you might ________ it in your car．（ ）
A．offerB．forgetC．borrowD．leave
Jerry will succeed in working out the problem ____ he gives up．（ ）
A．IfB．becauseC．soD．unless
We will have a sports meeting in October， but ______knows the date for sure．（ ）
A．everybodyB．nobodyC．anybodyD．somebody