Fill in the blanks.

(a) Burning of wood and coal causes …………… of air.

(b) A liquid fuel, used in homes is ……………

(c) Fuel must be heated to its …………… …………… before it starts burning.

(d) The fire produced by oil cannot be controlled by ……………

Give reasons.

(a) Water is not used to control fires involving electrical equipment.

(b) LPG is a better domestic fuel than wood.

(c) Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.

Explain how the use of CNG in automobiles has reduced pollution in our cities.

Compare LPG and wood as fuels.