Motion of the plates of Earth's crust is thought to be due to ...

[lak]

Motion of the plates of Earth's crust is thought to be due to
 
  a. the solar wind.
  b. convection from the hot interior.
  c. tides in the oceans.
  d. friction between wind and the land surface.
  e. Earth's magnetic field.

Question 2

Slow surface evolution is caused by
 
  a. wind erosion.
  b. plate tectonics.
  c. differentiation.
  d. wind erosion, plate tectonics, and differentiation.
  e. wind erosion and plate tectonics.

[rnehls]

Answer to Question 1

b

Answer to Question 2

e