7.Although the causes of cancer ____， we do not yet have any practical way to prevent it.
| A．are being uncovered | B．have been uncovering |
| C．are uncovering | D．have uncovered |
People have to _________ lots of hardship before they succeed.
| A．put up | B．come to terms with | C．enjoy | D．do with |
More natural resources should be _______use of to meet the increasing need of energy.
A putB broughtC takenD made
We must do as much as we can ____ our dreams.
| A．realize | B．to realize | C．to realizing | D．in realizing |
When he was there, he _____ go to that coffee shop for the corner after work every day.
| A．would | B．should | C．had better | D．might |
The country music is worth ___.
| A．being listened | B．listening | C．to listen to | D．listening to |