$54.\_\_\_$ and $\_\_\_$ are common derivatives of ethylene, used in the manufacturing of various plastics. $($a$)$ Ethanol, butadiene $($b$)$ Polyethylene, polypropylene $($c$)$ Butylene, acetylene $($d$)$ Methane, propane

$55.\_\_\_$ and $\_\_\_$ are petrochemical precursors primarily used in the production of synthetic rubber. $($a$)$ Ethylene, propylene $($b$)$ Butylene, acetylene $($c$)$ Propane, methane $($d$)$ Hydrogen, synthesis gas