The center of mass of the solar system is A) midway between ...

[vHAUNG6011]

The center of mass of the solar system is
 
  A) midway between the Sun and Jupiter
  B) exactly at the center of the Sun
  C) just outside the orbit of Mercury
  D) close to but not exactly at the center of the Sun

Question 2

What do we mean by The Oxygen Crisis in relation to the evolution of life on Earth?
 
  A) the extinction of older anaerobic life as oxygen builds up in the atmosphere
  B) the time period before the development of the ozone layer
  C) a period when evolution accelerated so rapidly that there was insufficient oxygen available
  D) the destruction of oxygen in the early atmosphere

[johnpizzaz]

Answer to Question 1

D

Answer to Question 2

A

[vHAUNG6011]

TYSM

[Joy Chen]

Gracias!