Question

The percentage of oxygen in the air does not change because

Oxygen is not used in any natural process
Oxygen used up in some natural process is renewed by another natural process
Oxygen used up in some natural process is replenished by the ozone layer
Oxygen used up in natural process Is negligible

give the answer correct

Answer 1

Answer:

oxygen used up in some natural process is renewed by another natural process.

Answer 2

there are more plants on earth