1. Air is odourless and [?]
2. Nitrogen is the [?] component of air.
3. Carbon dioxide constitutes [?] of air.
4. Inert gases are [?]
5. [?] turns limewater chalky.
6. The percentage of carbon dioxide in [?] air is 4%.
7. Inhaled air contains [?] oxygen than exhaled air.
8. A candle placed inside a [?] container will burn longer.
9. People caught for open burning of rubbish will [?]
10.Cigarette smoke contains tar, carbon monoxide and nicotine which are [?] to our health.