esci review

distance from a star where liquid water can exist in its liquid form

water allowed the first __ to thrive

heat from the surface of the earth

• internal heat

• external heat

heat from the sun

• internal heat

• external heat

ensures the adequate amount and flow of gases on earth

made up of all the water found on earth-on its surface, underground, and in the air

made up of all living organisms on the planet

composed of all the rocks, minerals, and soil on earth

body of gas that envelops earth

percent of nitrogen