The polymer used for making contact lenses for eyes is

Which factor imparts crystalline nature to a polymer like nylon?

Match List-$I$ with List-$II$:

List-$I$ Polymer	List-$II$ Type/Class
$A$. Nylon-$2$-Nylon-$6$	$I$. Thermosetting Polymer
$B$. Buna-$N$	$II$. Biodegradable polymer
$C$. Urea-formaldehyde	$III$. Synthetic rubber
$D$. Dacron	$IV$. Polyester

Choose the correct answer from the options given below:

Which one of the following is an example of thermosetting polymers?

The number average molecular mass of a polymer that contains $15$ molecules with each of mass $8,000$ and $15$ molecules with each of mass $80,000$ is: (in $,000$)

Bakelite is a type of .......