Question

Solve all questions answers except D.1

Answer 1

Answer:

2. Oxygen is essential for us and animals because due to its presence only we can breathe. It also helps in combustion.

3. There is a lot of air at the sea level or surface of the earth because it is holding the whole weight of the earth's atmosphere, that is why the pressure is more.

4. When we move to higher altitudes, the air pressure decreases due to the decrease in the weight of air.

5. Answer is related to 4th part. They carry so as in order to breathe.

Explanation:

Hope it helps.