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: Chemical weathering is the chemical disintigration of rocks. 
Sentence2: moss causes the chemical disintigration of rocks.
chemical

Sentence1: Human mating behavior also involves some competition. 
Sentence2: Human mating may lead to aggressive behaviors or displays of aggresion.
Human

Sentence1: DNA DNA DNA is a person's genetic fingerprint. 
Sentence2: a person's genetic fingerprint tells cells what to do.

fingerprint