Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Sentence1: adding salt to a solid decreases the freezing point of that solid.
Sentence2: Water density decreases with temperature and increases with salt content.
decreases

Sentence1: if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past.
Sentence2: Fossils are the remains of prehistoric life.
fossils

Sentence1: a gasoline lawn mower converts gasoline into motion.
Sentence2: Gasoline mowers can have as much emission as a car.
gasoline