Air is invisible.
People who regularly work in the open air do not suffer from sleeplessness.
The Army Air Corps, which became the U.S. Air Force, began in 1918.
Air as well as sunlight is, needless to say, indispensable to our daily life.
Because of the problem of air pollution, the bicycle may some day replace the automobile.
Hers was a nervous disease, and a change of air was an urgent need.
Thai Air celebrates its 50th anniversary this year.
An F-14 is a U.S. Air Force plane.
Evaporation from oceans, lakes, and rivers creates 90% of the water in air.
Incidentally, this room doesn't have anything like an air conditioner. All it has is a hand-held paper fan.
President aired his views on the war. The professor aired his controversial opinions and got fired.
There was an air of stress during the landing. She had an air of quiet confidence. I couldn't bear the air of anger and jealousy.
I'm thinking of going somewhere for a change of air, since my doctor advises me to.
Air, like food, is a basic human need.
If I go by air one more time, I'll have flown in an airplane five times.