Available Answers

1. 1.

   What is the term used for undesirable substances present in air?

2. 2.

   Name a gas produced by incomplete burning of fuels.

3. 3.

   Name any two gaseous pollutants.

4. 4.

   Mention the gases responsible for causing acid rain.

5. 5.

   Name any four sources of water pollution.

6. 6.

   Suggest two methods for making water potable.