Air and the respiratory system

3. Is a process by which air enters and leaves our body.
9. Oxygen is also found in _____. Living things that live in the ground are able to use this oxygen.
13. About 21% of air is made up of _____.
14. The number of times we breathe in one minute is our _____ rate.
16. The _____ help the body to take in oxygen and remove carbon dioxide.
17. _____ like frogs breathe through their lungs and moist skin
21. When there is light, plants use carbon dioxide and water to make food by a process called _____.
23. In most plants, stomata are found mainly on the underside of leaves.
24. The carbon dioxide is _____ from the body when we breathe out.
25. _____ have breathing holes in their bodies to take in air.
26. Living things are able to _____ on the Earth because there is air around them.
27. When there is no _____, plants do not make food.
28. The diver is able to _____ underwater with the help of an air tank.

1. When we exercise, our breathing rate increases.
2. _____ breathe through their moist skin.
4. About 78% of air is made up of _____.
5. _____ like whales and dolphins have lungs like us but they live in water all the time.
6. Fish take in oxygen in the water using their _____.
7. When we breathe in, air enters the body through the _____.
8. The air travels between the nose and the air tubes through the _____.
10. The _____ in the nostrils remove dust from the air we breathe in.
11. Oxygen in air is needed by living things to stay _____.
12. The water vapour becomes water droplets and forms a _____ when the surroundings are cold.
15. Air contains different types of _____.
18. The _____ transports the oxygen to all parts of the body.
19. There is water vapour in the air which we breathe _____.
20. Living things that live in water take in oxygen that is _____ in water.
22. In plants, the exchange of gases with the surroundings takes place through _____ openings found on leaves.