--Why does the river smell terrible?
--Because large quantities of water__________.
| A．have polluted | B．is being polluted | C．has been polluted | D．have been polluted |
The doctor recommended that you___swim after eating a large meal
| A．wouldn’t |
| B．couldn’t |
| C．needn’t |
| D．shouldn’t |
It never occurred to me ___you could succeed in persuading him to change his mind
| A．which |
| B．what |
| C．that |
| D．if |
___some people regard as a drawback is seen as a plus by many others
| A．Whether |
| B．What |
| C．That |
| D．How |
Though___to seeus,the professor gave us a warm welcome
| A．surprising |
| B．was surprised |
| C．surprised |
| D．being surprised |
Listening to loud music at rock concerts___caused hearing loss in some teenagers
| A．is |
| B．are |
| C．has |
| D．have |