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) Fire produced by oil cannot be controlled by ________ _.
Fill in the blanks.
(a) The slow process of conversion of dead vegetation into coal is called__________.
(b) Coal and petroleum are formed from the dead remains of organisms and are known as __________.
(c) The black thick liquid with __________ smell is known as coal tar.
(d) During the processing of coal to get coke, coal tar and __________ are also obtained.
(e) The process of separating the various constituents of petroleum is known as __________.
(f) Excessive burning of fossil fuels is a major cause of __________.
Fill in the following blanks with suitable words :
(a) A fuel must be heated to its___ before it starts burning.
(b) The most common supporter of combustion around us is___
(c) Fire produced by burning oil cannot be controlled by___
(d) A liquid fuel used in homes is___
(e) The amount of heat evolved when 1 kg of a fuel is burnt completely is called its___
(f) The substances which vaporise during burning, give___
(g) Burning of wood and coal causes___ of air.