Write the structures of monomers used for getting the following polymers: (a) Novolac (b) Neoprene (c) Buna-S OR (a) Write one example each of: (i) Cross- linked polymer (ii) Natural polymer (b) Arrange the following in the increasing order of their intermolecular forces: Terylene, Buna-N, Polystyrene (c) Define biodegradable polymers with an example.