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: healing requires rest. 
Sentence2: Healing and cell regeneration follows.
healing

Sentence1: Insulin is a hormone that helps cells absorb sugar from the blood. 
Sentence2: the pancreas produces a hormone that helps cells absorb sugar from the blood.
absorb

Sentence1: tadpole changes into a frog. 
Sentence2: Tadpoles become frogs after 4 months.

frog