Which of the following are poor conductors of heat and electricity?

1. metallic minerals
2. non-ferrous minerals
3. non-metallic minerals
4. none of the above

Choose from the following the incorrect statement regarding mineral conservation:

1. The meaning of 3Rs is to reduce, recycle and reuse minerals.
2. There is more use of alternative sources of energy.
3. There is maximum use of petroleum as it is the main source of energy.
4. There is dependence on hydroelectricity.

Which of the following minerals is mined by sifting through the sand and mud in the river beds?

1. coal
2. gold
3. copper
4. petroleum

Burning of coal and petroleum leads to which one of the following harmful events for the entire world?

1. results in global warming
2. produces smoke
3. produces energy
4. runs industries