The recent alternative explanation for the disappearance of ...

[abc]

The recent alternative explanation for the disappearance of Earth's early atmosphere sees this as the primary causative agent:
 
  A) volcanic outgassing.
  B) collisions of Earth with other large bodies.
  C) periodic energy pulses from the surface of the Sun.
  D) gravitational attraction of the Moon.

Question 2

This was probably the predominant gas in Earth's earliest atmosphere:
 
  A) argon.
  B) hydrogen.
  C) water vapor.
  D) nitrogen.

[zacnyjessica]

Answer to Question 1

Answer: B

Answer to Question 2

Answer: B