The bottoms of clouds are often gray because A) precipitation is ...

[ashley]

The bottoms of clouds are often gray because
 A) precipitation is imminent.
  B) they are over dark portions of the Earth's surface.
  C) the bottoms of clouds are denser than the tops, and thus absorb more light.
  D) multiple scattering has removed most light before it reaches the bottom of the cloud.
  E) droplets or crystals within the cloud have dispersed most of the available light.

Question 2

Clouds in sunshine look white because
 A) light of all colors is multiple scattered within the cloud.
  B) they contain white pigments.
  C) they have a low index of refraction.
  D) they are contrasted against blue sky.
  E) they are not able to absorb the specific frequency of white light.

[chinwesucks]

Answer to Question 1

D

Answer to Question 2

A

[ashley]

Excellent

[cdmart10]

Gracias!