List conditions under which combustion can take place.
Conditions necessary for combustion are :
(i) Presence of combustible substance.
(ii) Attainment of ignition temperature.
(iii) Proper supply of air to provide oxygen.
Fire produced by oil cannot be controlled by ___________ .
A liquid fuel, used in homes is __________
Burning of wood and coal causes __________ of air.
Fuel must be heated to its __________ before it starts burning.
