At which stage in its life cycle, does the silkworm yield the fibre of commerce?

Light weight bullet proof helmets and jackets use which of the following fibres for their production ?

When hot water is placed into an empty water bottle, the bottle keeps its shape and does not soften. What type of plastic is the water bottle made from?

Select the pair of fibres obtained from the stem of a plant :

What is the ‘fibre’ used to make bulletproof jackets?

Which one of the folowing is an example of melamine used for making floor tiles?