(i) From the given passage, we can conclude that the students show awareness about the enviromnent.
(ii) A polymer that can be decomposed by microorganisms within a definite period of time, so thet the polymer or its deraded product does not cause any harm to the environment, is called a bio-degradable polymer. For example, poly - `beta` - hydroxybutyrate - Co - `beta` - hydroxy valerate (PHBV) is a bio-degradable aliphatic polyester.
`[{:(-CH_(2) -CH_(2)-C-O-CH-CH_(2)-CH-C-),(" "|" "||" "|" "||),(" "CH_3" "O" "CH_2-CH_3),(" "PHBV):}]_(n)`
(iii) Polythene is an addtion polymer that is formed by addition of ethene molecules.
`underset("Polythene Polymer")underset("Ethane")(nCH_2=CH_2)overset("polim erisation")tounderset("Re peating unit")(n[-CH_2-CH_2-])to[CH_2-CH_2]_n`