Questions

Terylene and nylon are synthetic fibres produced by a process of polymerisation. Terylene is a polyester and nylon, a poyamide.

Silk is purely a natural product obtained from silk worms.

Rayon is a man-made material which consists of purified cellulose in the form of long fibres. Cellulose occurs in the cell wall of plants. Rayon fibre is chemically identical to cotton but has a shine like silk. Since it is  basically derived from a natural source (cellulose) it is called a regenerated fibre.

One who dies for a noble cause is called a martyr. He is a person who dies fighting for what they believe in like advocating religious or other beliefs, refusing to renounce, etc...

Central Processing Unit is the main part of the computer.

CPU chip or main processor is that part in the computer which performs or executes all the instructions or programs.

Because of its being pollution free and  combustion efficient, Hydrogen gas is  called fuel of future. Because of its origin in marshy places, Methane is called as 'Marsh Gas'.