Identify the natural source of ascorbic acid from following.

Identify the monomers used to prepare bakelite from the following.

Which among the following is NOT a polyester polymer ?

If $x$, y, z are the sides of a right angled triangle, where z is the largest side, then $\dfrac{1}{\log_{x+z} y} + \dfrac{1}{\log_{z-x} y} =$