Which is the most economical method of removing solid matter from water?

Oiled paper is?

What happens in most toothpastes to prevent tooth decay?

Halogens are belonging to:

The gas which is present in both the natural gas and the bio-gas is

Solutions having the same osmotic pressure at a given temperature are called_____.

Read the following questions carefully and answer them. 

The gas used for artificial fruit ripening of green fruit is —

During uniform motion of an object along a straight line, its ___________ remains constant with time.