____is certain is ___prevention is more important than treatment .
| A．It;that | B．What;that | C．As;what | D．What;what |
The result what he said would lead _____ his regret in the future.
| A．is | B．to be |
| C．to being | D．to was |
The work he paid special attention _____ to nothing.
| A．came | B．to come |
| C．to coming | D．to came |
“May I go and play with Dick this afternoon, Mum?” “No, you can’t go out _______ your work is being done.”
| A．before | B．until |
| C．as | D．the moment |
“I’m going to the post office.” “_______ you’re there, can you get me some stamps?”
| A．As | B．While |
| C．Because | D．If |
New medicines and instruments ______ every day to extend life.
| A．develop | B．are being developed |
| C．are developing | D．have developed |