2Questions about AIR (F3 chemistry) [十萬火急!!!!!!!]

1) Air is a mixture which contains about 78% of Nitrogen gases and 22% of Oxygen gas, the remaining are Carbon Dioxide, Water Vapour, and other inert gases like Argon.
* Inert gases means they are very stable, very unreactive.

2)
In daily life:
Of course oxygen is necessary for us to survive. However, the breathing action of our bodies is maintained by concentration of carbon dioxide, as CO2 is a stimulus to medulla to control our breathing rates and depths. Thus, both Oxygen and Carbon are necessary for our life.
Also, oxygen is essential for combustion.
Carbon dioxide is also required for organisms with photosynthetic pigments to carry out photosynthesis. These organisms are the producer of food chains, which means they are the food sources of any other heterotrophs.

In school lab, oxygen in air is required to light up a Bunsen burner

Q2 What is the uses of air in our daily life and in the Lab?

In lab, we can use air in bunsen burner (open the air hole) to get a blue flame

it's quite good! thankyou!

ans 1:
Air is a mixture of different gases, such as ~78% of nitrogen, ~28% of oxygen and other gases (carbon dioxide, water vapour...) etc.
ans 2:
daily life:
breathing, use for separate useful gases (e.g. Oxygen, nitogen, Argon....etc) in fractional distillation of air in industry, help for combustion (mainly oxygen to do so), ... etc
Lab:
You mean school lab? I think there is no such experiments in school lab as numerous gases cannot be separated in school laboratory by using simplae method.