air travel

The great virtue of air travel is speed.

乘飞机旅行最大优点是速。

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

别适合长途乘车，乘飞机时使用。

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

本世纪空中飞行似乎使世界变小了。