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

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.

Silver and gold are malleable and …………… .

1. heavy metals
2. conductors of electricity
3. found in sedimentary rocks
4. ductile