Without facts, we cannot form a worthwhile opinion for we need to have a factual knowledge ________ our thinking.
| A．which to base on | B．which to be based on |
| C．on which to be based | D．on which to base |
Modern teaching equipment as well as tens of computers _______ to the village school last week.
| A．were sent | B．was sent |
| C．has sent | D．had been sent |
The number of air crashes that _______ in developing countries _________ increasing.
| A．happens; is | B．happen; is |
| C．happens; are | D．happen; are |
Bill suggested ________ a meeting on what to do for the Shanghai Expo during the vacation.
| A．having held | B．to hold |
| C．holding | D．hold |
_________many times, he finally understood it.
| A．Told | B．Telling |
| C．Having been told | D．Having told |
This morning, I rushed to the library, only ________ that its door was still locked.
| A．to be found | B．to find |
| C．finding | D．found |