Farmers with small holdings of land do the separation of grain and chaff by

some insects and animals which act as carriers ________of disease causing microbes.

the bread or idli dough rises because of

Rayon is different from synthetic fibres because

phosphorus is a very reactive ________

metal react with sodium hydroxide to produce__________gas

iron is ___________________ reactive than copper.

The process of separating the various constituents factions of petroleum is known as_______________

the calorific value of a fuel is expressed in a unit called

burning of wood and coal causes _______ of air

migratory birds fly to far away places because of_________ changes.