What is the minimum distance (in metres) required to hear an echo? 

The major component used in preparation of different types of glasses is :

Who invented dynamite? 

A mixture of water and alcohol can be separated by 

The manufacture of iron from iron ore involves the process of 

In which state Goal Gumaj situated ?

In which of the following fields Nobel Prize is not given? 

The lactose is made , from . . . .