$10.$ In alkylation, $\_\_\_\_\_\_\_\_$ and $\_\_\_\_\_\_$ are combined in the presence of an $\_\_\_\_\_\_\_\_$ to produce high$-$octane gasoline components.

$11.$ Polymerization in the petroleum industry involves linking small molecules called $\_\_\_\_\_\_\_\_$ into larger $\_\_\_\_\_\_$ to create products like $\_\_\_\_\_\_\_\_.$

$12.$ Isomerization improves the quality of gasoline by changing straight$-$chain hydrocarbons into $\_\_\_\_\_\_\_\_,$ which are more $\_\_\_\_\_\_$ and have a higher $\_\_\_\_\_\_\_\_.$

$13.$ Naphtha, used as a feedstock in the $\_\_\_\_\_\_\_\_$ industry, is derived from $\_\_\_\_\_\_$ and serves as a primary material for producing $\_\_\_\_\_\_\_\_.$