Balance of carbon dioxide and oxygen in nature

1. All living things breathe in _________ and breathe out _____________ in respiration.

2. In photosynthesis, plants make their own food. They absorb _________________ in the air and give out ______________ in the air.

3. As a result, it maintains the balance of ___________ and _____________ in nature.

4. Our earth has just the right temperature for living things, why? It is because of the " ________________________".

5. Examples of greenhouse gases include ________________.

6. Some human activities, such as ____________________ are changing Earth’s natural balance of carbon dioxide and oxygen in nature.

7. These human activities produce extra _______________ that causes the atmosphere to trap more __________ and the average temperature of the Earth increases.

8. It enhances the _____________________ and leads to _______________.