When earth is 147 million km from the sun, it is at its

a~ aphelion.

b~ perihelion.

c~ astronomical unit.

d~ ellipse.

Blank is a naturally occurring gas that's found in most soils and rocks and can cause lung cancer

All of the following are reasons why deserts extremely susceptible to wind erosion except a. they lack major root systems b. they contain thin, dry soil c. they have very few plants and trees d. they are extremely hot and lack water

Which component of a milankovitch cycle is related to periodic ice ages throughout earth’s history?