Some researchers believe that there is no doubt___ a cure for AIDS will be found.
| A．which | B．that | C．what | D．whether |
It is likely that water is not ____ endless resource, nor ____ that can be made once more．
| A．the; / | B．an; one | C．an; that | D．/; one |
How long ______ teaching? Forty years.
| A．he will have been | B．will have he been |
| C．will have been he | D．will he have been |
An operation is usually performed by a ______.
| A．doctor | B．dentist | C．surgeon | D．scientist |
He is the manager of the factory. He is ______ it.
| A．charged with | B．in charge of | C．charged | D．in the charge of |
The whole hall wants ______.
| A．to be cleaning | B．to be cleaned |
| C．being cleaned | D．to clean |