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: Mammals generate heat mainly by keeping their metabolic rate high. 
Sentence2: food keeps mammals' metabolic rates high.
Mammals

Sentence1: Weather Clear weather usually means good visibility. 
Sentence2: High pressure systems can cause good visibility.
good

Sentence1: when a river floods , that river deposits soil in flood plains. 
Sentence2: Flatplains are higher lands which are only flooded by the rivers during flood season.

flood