Why does the Earth have abundant liquid water at its surface whereas Mars and Venus have none? (check all that are true)
a) Mars and Venus didn't have water when they formed.
b) Venus is too close to the Sun, so it is too hot for liquid water.
c) Earth is in the habitable zone where liquid water is stable.
d) Mars is too close to the Sun, so it is too hot for liquid water.
e) Mars and Venus are outside of the habitable zone.