When I worked as the general manager of the firm, I sometimes had _____ to visit London on business.
| A．opportunity | B．possibility | C．occasion | D．chance |
22. He demanded that such things_____ from happening again.
| A．prevented | B．prevent | C．be prevented | D．should prevent |
21._____by a desire to learn, he was not interested in children’s play and adventure when he was young.
| A．Driven | B．Driving | C．To drive | D．To be drive |
20. The flu is believed________by viruses.
| A．causing | B．being caused | C．to be caused | D．to cause |
19. They________a lot of suggestions for improving the workers’ living conditions.
| A．put out | B．put forward | C．put on | D．put in |
18. After having gone____-far, I didn’t want to turn back.
| A．enough | B．thus | C．that | D．Much |