3（）

A．Train travel will prove much more comfortable than air travel.
B．Passengers will feel much safer on board a train than on a plane.
C．Rail transport will be environmentally friendlier than air transport.
D．Traveling by train may be as quick as, or even quicker than, by air.

A．we increase the insulation of walls and water pipes
B．we choose simpler models of electrical appliances
C．we cut down on the use of refrigerators and other white goods
D．we choose the most efficient models of refrigerators and other white goods