Question

1 How long after the formation of Earth did the first life appear?

2 Suggest how we know when the different kinds of organisms first appeared on
Earth.
Fears ago
mple animal-like
red.
3 Up to about 3000 million years ago, there was no oxygen in the Earth's
atmosphere. Today, about one fifth of the atmosphere is oxygen gas.
Use the information on page 6 to suggest what caused this change.

Answer 1

1.After 10 years

2.we have our ancestors who see it

3.the change was caused by the trees and the good nature surrounds our planet

Note that science believe that every living organisms on earth is made by bacteria