1.The great virtue of air travel is speed.

1.乘飞机最大优点是速度快。

2.The innovation of air travel during this century has made the world seem smaller.

2.本世纪发明空中飞似乎使世界变小了。

3.It does not clag bood circulation,especially it suits long-distance bus traveling and air traveling.

3.特长途乘车，乘坐飞机时使用。