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: Boiling water can cause burns. 
Sentence2: heating water can cause burns.
water

Sentence1: Competition may lead to aggressive behaviors or displays of aggression. 
Sentence2: Aggression Aggression and violence often go together.
aggression

Sentence1: Mollusks are invertebrates such as the common snail. 
Sentence2: clams are mollusks.

Mollusks