Yet up at about five-thousand-four hundred meters the air pressure is only about half of what it is on the ground.

VOA: special.2011.04.06

When melting snow-crystals or raindrops fall through very cold air, they freeze to form small particles of ice, called sleet.

VOA: special.2011.01.11

The group's recent "State of the Air" report said Pittsburgh has the worst short-term fine particle pollution in the country.

VOA: special.2009.07.13

During one week in nineteen forty-eight, poisonous air in a nearby town killed twenty people and sickened six thousand others.

VOA: special.2009.07.13

Because of the open-air stage, actors had to shout very loudly and make big motions to be heard and seen by all.

VOA: special.2010.01.06

For every increase of five degrees Celsius in air temperature, the patients had a seven and one-half percent higher risk of migraine.

VOA: special.2009.03.18

He was born in Berkeley. The college website says he accepted Islam in nineteen seventy-seven while serving in the United States Air Force.

VOA: special.2010.08.05

They were suspended from ropes as they used heavy air-powered hammers to break any loose rock away from the face of the canyon walls.

VOA: special.2009.08.12

The air -- smelling of coffee and fried food -- wrapped itself around his head.

VOA: special.2010.05.29

The air - smelling of coffee and fried food - wrapped itself around his head.

VOA: special.2009.01.31

Engineers on the ground designed a way the astronauts could connect air-cleaning devices from the command module to the air system in the lunar module.

VOA: special.2009.07.22

The International Union Against Cancer says about seven hundred million children breathe smoke-filled air.

VOA: special.2010.03.09

Nine days after take-off, Voyager landed smoothly at Edwards Air Force Base in California.

VOA: special.2010.10.06

Let sanitized cans air-dry for at least one hour before opening or storing them.

VOA: special.2010.07.19

Visitors to Washington,D.C., in the summer often want to stay inside air-conditioned museums.

VOA: special.2009.09.21

At about nineteen-thousand meters, the air is so thin and the amount of oxygen so small that a person needs a lot of special equipment to survive.

VOA: special.2011.04.06

Marconi sent the first radio communication signals through the air in eighteen ninety-five.

VOA: special.2010.01.31

Some travel guides have described Luxor as the world's largest "open-air museum."

VOA: special.2011.03.08

Israel says its air and ground attacks are targeting only Hamas-related targets.

VOA: special.2009.01.10

His S-38 amphibian flew through the air and then landed on water.

VOA: special.2010.09.10

His father was a high-level air force officer in the Pakistani military.

VOA: special.2010.05.08

Donald Slayton, another Air Force flier, worked on the long-range Atlas Rocket.

VOA: special.2009.06.10

From high in the air, visitors can clearly see the third area of the park -- a high broad flat rock known as the Island in the Sky.

VOA: special.2009.04.15