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.

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

Choose the correct combination.

1. only A1 and B2 are correct.
2. only B2 and C3 are correct.
3. only A1 and D4 are correct.
4. only B2 and D4 are correct.