Keep your kids away from the ________ knives．They may cut themselves．

A．firm

B．pure

C．sharp

D．good

The single most important factor that contributes to success is ________ you do every single day．

A．that

B．what

C．which

D．how

Peter ________ a little money every month so that he can buy a car of his own in the near future．

A．sets aside

B．sets about

C．sets off

D．sets out

Most smokers are perfectly aware ________ the danger of smoking．

A．at

B．of

C．in

D．with

She heard him declare that he didn't want ________ her the next day and that he felt more than just the desire ________ her．

A．to leave, to please

B．leave, pleasing

C．to leave, please

D．leaving, to pleased

Tom hid himself behind the door, ________ he could hear the steps of his mother clearly．

A．from which

B．from there

C．where

D．from where

The professor recommends that we ________ the experiment until it is carefully designed．

A．don't start

B．not start

C．will not start

D．would not start

With so many forms ________ , many students feel at a loss before the 2012 college entrance exam．

A．filling in

B．filled in

C．to fill in

D．to be filled in

As far as I am ________ , teaching children is something worthwhile．

A．concern

B．concerning

C．concerns

D．concerned

The country life we ________．The differences between rural and urban areas are disappearing．

A．were used to have changed

B．used to change

C．used to changing

D．were used to has changed