The air transportation of our country is developed in highest speed in current world area.

What does the speaker encourage employees to do？

A．Sign a petition

B．Use public transportation

C．Write a letter to the mayor

D．Volunteer to clean up Olivia Street

According m Tim Holmes of Ford Europe, battery-powered cars

A．will be the main transportation vehicles in the future.

B．will not be the main transportation vehicles in the future.

C．will be good to the environment in the future.

D．will replace petrol-powered vehicles in the future.

A.on the air

B.on air

C.onto the air

D.on the airs

A．On foot and by boat.

B．By car and on foot.

C．By air and by car.

D．By air and by bus.

Air moves under such conditions that______.

A．there is air pressure

B．the air is heavy

C．air pressure doesn't remain the same all the time

D．air comes up and down

The automobile is now the main cause of air pollution.

A．Y

B．N

C．NG

A.air

B.rock

C.water

D.soil