Mr. White spent about one hour and a half _________ the accident report yesterday evening.
| A．write | B．written | C．writing | D．to write |
To live a green life, we try_________ more energy and produce less pollution.
| A．to save | B．save | C．saves | D．saved |
In recent years the environmental pollution has been _________ than before.
| A．so serious | B．serious | C．more serious | D．too serious |
．It is said that a wooden bridge_________ over the river in the mountain village soon.
| A．build | B．will be built | C．will build | D．built |
I’d like to travel by air _________ it usually costs a lot of money.
| A．so | B．though | C．until | D．or |