What are insulated foam cups most likely made out of? polyethylene polystyrene nylon thread vulcanized rubber

Answer is: polystyrene.

Expanded polystyrene is used to manufacture foam cups.

Polystyrene production is several million tonnes per year.

Polystyrene is a synthetic aromatic hydrocarbon polymer made from the monomer styrene.

Styrene (ethenylbenzene) is an organic compound with the chemical formula C₆H₅CH=CH₂. It is a colorless oily liquid.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

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