To make contributions to the protection of the environment, the company encourages its workforce to make the _______ to alternative means of transportation such as carpooling or biking to reduce air pollution.
| A．switch | B．conclusion |
| C．variety | D．enquiry |
For a long time they walked without sayingword. Jim was the first to breaksilence.
| A．the; a | B．a ; the | C．a ; 不填 | D．the; 不填 |
It’s based on the idea ______ all people are created equal, ______ is accepted by most people.
| A．that; which | B．which; which | C．which; when | D．that; that |
______ the ancient Egyptians built the pyramids puzzled people for centuries.
| A．Whether | B．What | C．How | D．Where |
______ I’m well again, I can go on with my work.
| A．Even if | B．As though | C．Ever after | D．Now that |
The government has to close those small factories to prevent the water of the river ______.
| A．polluting | B．from polluting | C．being polluted | D．polluted |