$55.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ 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

$56.$ The primary purpose of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ and $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ in the petrochemical industry is to serve as precursors for various chemicals such as methanol and ammonia. $($a$)$ Synthesis gas, hydrogen $($b$)$ Ethylene, butylene $($c$)$ Acetylene, propylene $($d$)$ Methane, propane

$57.$ The process of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ involves the conversion of methane and steam into synthesis gas, while $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ involves the conversion of hydrocarbons into smaller molecules. $($a$)$ Steam reforming, catalytic cracking $($b$)$ Hydrocracking, steam reforming $($c$)$ Catalytic reforming, steam cracking $($d$)$ Steam cracking, hydrocracking

$58.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ and $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ are common petrochemical products derived from naphthenes, commonly used as fuels for various purposes. $($a$)$ Gasoline, diesel $($b$)$ Propane, butane $($c$)$ Methane, ethane $($d$)$ Jet fuel, kerosene