However，at times this balance in nature is _______ resulting in a number of possibly unforeseen effects.
| A．troubled | B．disturbed | C．confused | D．puzzled |
The decision was made ______ soon after the meeting was over. Who was made_____ the decision soon after the meeting was over?
| A．to know, known | B．known, to know | C．known, known | D．to know, to know |
.Not ______ beautiful, the building is ______ now.
| A．looking, being built | B．looked, being built |
| C．being looked, building | D．looking, built |
The conference has been held to discuss the effects of tourism ______ the wildlife in the area.
| A．in | B．on | C．at | D．with |
.Wait till you are more ______. It’s better to be sure than sorry.
| A．inspired | B．satisfied | C．calm | D．certain |
.She will tell us why she feels so strongly that each of us has a role ______ in making the earth a better place to live.
| A．to have played | B．to play | C．to be played | D．to be playing |