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


[Q]: Sentence1: measuring the hardness of minerals requires scratching those materials. 
Sentence2: To figure out the hardness of a mineral, the Moh's scale of hardness is used.
[A]: minerals


[Q]: Sentence1: damming a river can cause a lake to form. 
Sentence2: The beavers live on this side, and create dams.
[A]:
damming