Micro-organisms friends and foe

Which is the following plastics is used for making electric switches ?

• teflon

• melamine

• pet

• bakelite

Which of the following is not a synthetic fibre ?

• nylon

• flax

• acrylic

• polyester

The man-made fibre rayon is chemically identical to :

• wool

• silk

• jute

• cotton

Which of the following is not a natural fibre ?

• cotton

• wool

• silk

• rayon

Which of the following is a thermoplastic polymer ?

• polyvinyl chloride

• polystyrene

• polyethylene

• polypropylene