The two principal ways to describe Earth’s structure are based on the _______.
a. chemical composition and thickness of layers
b. chemical composition and mechanical properties of layers
c. mechanical properties and thickness of layers
d. the composition and viscosity of minerals

Question

The two principal ways to describe Earth’s structure are based on the _______.
a. chemical composition and thickness of layers
b. chemical composition and mechanical properties of layers
c. mechanical properties and thickness of layers
d. the composition and viscosity of minerals

wolfe8 · Answer

I'm not sure, but I would guess A. Did you try looking it up?

beccaboo333 · Answer

http://chuma.cas.usf.edu/~juster/S2/earth.html <- I would agree with A as well.