The question that puzzled them is ____ they can get rid of the air pollution in the area.
| A．how is it that | B．that how | C．what is it | D．how it is that |
Few people have ever ________deep into this well, for it is extremely dangerous.
| A．risked going |
| B．tried to go |
| C．trys going |
| D．risked to go |
Most people didn’t accept the theory when it was first ________.
A. set about
B. set off
C. put forward
Gun control is a subject ________ Americans have argued for a long time. (2009 .陕西)
| A．of which |
| B．with which |
| C．about which |
| D．into which |
More and more rich people have promised to ________their wealth after death to help the poor and the disabled.（2013．河北衡水中学）
| A．give away |
| B．give up |
| C．give out |
| D．give in |
---Look! He’s running so fast!
---Hard to ________ his legs were once broken.
| A．know |
| B．imagine |
| C．realize |
| D．find |