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

Sentence1: drought is when amount of precipitation decreases. 
Sentence2: Drought decreases the availability and abundance of the natural food supply.
drought

Sentence1: a switch is used to start the flow of current in an electrical circuit. 
Sentence2: a switch directs current.

switch