1.   John watched a swinging door compress the air behind her.

2.   Excess electricity can also be used to compress air in an underground store.

3.   However, air can be compressed.

4.   In simple terms, a supercharger compresses air before it enters the engine, creating a denser fuel-air charge that ignites more explosively during combustion.

5.   On descent from the Appalachians, where barometric pressures are relatively lower due to altitude, winds warmed as air was compressed at lower altitudes.

6.   The engines operate by compressing intake air to high pressures before injecting fuel into the combustion chamber.

7.   They say that the pressure of seawater rushing in compressed the air in the hull and reduced the chances for survival beyond a few days.

8.   Water entering the tank compresses air in the cylinder.

9.   Atmospheric air is compressed in the oxygen trains and then liquified oxygen is distilled out in cold boxes.