polycyclic

"Gasoline is a hydrocarbon fuel used in many cars. "

"The baker was involving the dough around a metal form to create a spiral-shaped pastry. "

"Burning natural gas, which is mostly made of hydrocarbons, provides heat for many homes. "

"My grandmother puts mothballs in her closet to protect her winter coats from moths. "

"The incomplete report caused delays in the project. "

"The chemistry class focused on how different elements combine to form new substances. "

"Grandma used naphthalene to keep moths away from her woolen sweaters. "

"Factory chimneys released pollutants into the air, making it difficult to breathe. "

"To explain a chapter of the Bible."

"The main ingredient in Grandma's famous chocolate chip cookies is butter. "

"Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom and a chlorine atom."

""During the war, the refugees lived in guarded compounds for their safety." "