$A$ polymer with high chemical stability has a melting point $(M.P.)$ of $327\ ^\circ C$ and the density of a completely crystalline sample is $2.3\ g/cm^3$. It is:

Which of the following polymers does not contain an $N$ atom?

Monomer units of $Dacron$ polymer are :

Match List-$I$ (polymer) with List-$II$ (monomer/s) and select the correct option:
| List-$I$ (polymer) | List-$II$ (monomer/s) |
| :--- | :--- |
| $(A)$ Bakelite | $(I)$ $2$-Methyl-$1,3$-butadiene |
| $(B)$ Natural rubber | $(II)$ Glycine + Aminocaproic acid |
| $(C)$ Glyptal | $(III)$ Phenol + formaldehyde |
| $(D)$ Nylon $2$-Nylon $6$ | $(IV)$ Phthalic acid + ethylene glycol |

Ebonite is ........ .

The structures of some important polymers are given. Which one represents Buna-$S$?