(a) Terylene and PET are polyesters. Polyester is the synthetic fibre which contains the organic group similar-to those which give fruits their sweet smell. PET is a very familiar form of polyester. It is used for making bottles and utensils which is replacing materials like glass.

(b) Nylon is a polyamide. Nylon is the first fully synthetic fibre. It was prepared from coal, water and air. It is used for making parachutes and rock climbing ropes.

(c) Acrylic is used as a substitute for wool. It is a synthetic fibre which appears to resemble wool. It is flexible, resistant to moth, oil and chemicals. The clothes made from acrylic are relatively cheap and are available in a variety of colours.

(d) PET is a material used as a substitute for glass. It is a form of polyester. Polyester is the synthetic fibre which is made up of repeating units of a chemical called an ester. Esters are the chemicals which give fruits their smell. PET is used for making bottles, utensils, films and wires.