When animals and plants are rotten in the absence of air, there produces a gas called

Fossil fuels are rich in carbon and

A. nitrogen

B. hydrogen

C. nitrogen

D. oxygen

Thousands of mirrors or curved metals are used to focus solar energy to make it very hot, in

A. solar cells

B. solar heater

C. solar furnace

D. solar battery

Wind is beneficial resource of energy as it doesn't cause

A. pollution

B. echo

C. noise

D. sound

Hot water or steam carrying geothermal energy often comes up to surface in

A. New Zealand

B. Ice land

C. Germany

D. both a and b

Fossils fuel is an important source of energy for

A. transport

B. homes

C. industries

D. all of them