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: Hair helps to insulate and protect the body. 
Sentence2: most mammals have insulation that also protects the body.
body

Sentence1: Ejaculation allows males to reproduce. 
Sentence2: propelling sperm from the epididymes allows males to reproduce.
allows

Sentence1: Composting is simply the natural decomposition of organic matter. 
Sentence2: Composting increases the amount of organic matter in soil.

Composting