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.

Q: Sentence1: For instance, glucose is a sugar. 
Sentence2: insulin helps cells take up sugar from the blood.

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

A: body
****
Q: Sentence1: Menopause occurs when menstruation stops occurring, usually in middle adulthood. 
Sentence2: Hot flashes can occur when menstruation stops occurring.

A:
menstruation
****