atmosphere

A gas in the atmosphere we breathe is called

• carbon dioxide

• oxygen

• magnesium

• helium

The layers of gas that surround Earth is called

• hydrosphere

• mesosphere

• air

• atmosphere

Earth's _________________ pulls the air we need to breathe down to Earth

• gravity

• atmosphere

• air

• hydrosphere

This is where land and sea meet

• altitude

• valleys

• sea level

• at Ms. Buettner's house

The distance above sea level is called

• atmosphere

• air

• mountains

• altitude

The altitude of sea level is ____________ feeet

• 0

• 20

• 30

• 40

There is _____________ gas at sea level

• less

• more

• good

• bad

The __________________ the altitude the harder it is to breathe

• higher

• lower

• better

• worse

Astronauts have to wear tanks containing ______________ when they are in outer space

• nitrogen

• carbon dioxide

• oxygen

• methan

_____________________ can be dissolved in water and is an important ingredient in soda

• oxygen

• carbon dioxide

• methan

• water