The useful substances that are obtained from petroleum are

(a)  

Petroleum is formed at the bottom from the remains of a tiny organism

(a)  

Coal, Petroleum and Natural gas are also called as

(a)  

Petroleum is also known as

(a)  

Shoe polish is made from

(a)  

The slow process of conversion of vegetation to coal is called

(a)  

In manufacturing of steel this is used

(a)  

Petroleum is separated into various components by a technique called

(a)  

Natural gas is trapped between

(a)