Combustion

1. Gaseous fuels are considered the best.Write four poins in support of your answer.
2. What causes smog in winters?
3. If the amount of carbon dioxide increases in the atmosphere,what can be the effects of it?
4. What is global warming?
Write it's one useful and one harmful effect of it.
5. What is acid rain? Write it's two harmful effects.
6. What is CNG? Write three uses of CNG.

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