10
QuizMultiple Choice

Spheres of Earth

Question 10 of 10 • MO-Earth and Space Science A

Which event in Earth’s history most directly allowed life to exist on land?

Answer
A
Earth’s temperatures increased, causing widespread evaporation.
B
Earth collided with a large object, forming the moon.
C
Single-celled organisms released oxygen into the air when they photosynthesized.
D
Single-celled organisms absorbed harmful gases from the air when they first formed.