21 percent of air is..............................
21 percent of air is oxygen
Living organisms such as humans and animals need air for......................
Living organisms such as humans and animals need air for respiration.
Air is mainly composed by..............., ..............and small amount of some ..............
Air is mainly composed by oxygen, nitrogen and small amount of some gases.
Which gas is produced from the respiration of humans and animals?
Carbon dioxide.
Name some other gases in the air besides nitrogen and oxygen.
Carbon dioxide, water vapour.........
Plants need carbon dioxide in the............................... process.
photosynthesis
78 percent of air is...............................
78 percent of air is nitrogen.
Air is essential for living................. like humans, animals and plants.
organism
