I didn’t know it could do terrible ______to your heart and lungs or ______was more difficult for smoking couples to become pregnant.

. Our teacher has a __________ for thinking up ways _________ his speeches attractive.

The environment will ______ one’s character.

Standing on the top of the Oriental Pearl Tower, you will get a wonderful _______ of Shanghai city.

 A ______ to this problem is expected to be found before long.