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.

[EX Q]: Sentence1: Hair helps to insulate and protect the body. 
Sentence2: most mammals have insulation that also protects the body.
[EX A]: body

[EX Q]: Sentence1: Mutations are essential for evolution to occur. 
Sentence2: Genes are altered for evolution to occur.
[EX A]: evolution

[EX Q]: Sentence1: Nerve impulses are electrical in nature. 
Sentence2: stimulus is turned into an electrical nature.
[EX A]:
electrical