You see this sticker (given on the right) on the front windshield of a car. What does it mean?

1. The car is a commercial vehicle.
2. The car uses Compressed Natural Gas as fuel.
3. The car is not fuel efficient.
4. The car uses Cooled Nitrogen Gas as fuel.

What is meant by conventional sources of energy? Name any two conventional sources of energy.

Give a geographical reason for each of the following:

Anthracite is used for domestic purposes.

Give a geographical reason for each of the following:

Oil refineries are located close to oilfields or near ports.