instruction:
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.
question:
Sentence1: Aggression is behavior that is intended to cause harm or pain. 
Sentence2: Verbal violence is behavior that is intended to cause harm or pain.
answer:
behavior


question:
Sentence1: Generally, pheromones are volatile substances. 
Sentence2: Male dogs use volatile substances in urine to mark their territory.
answer:
substances


question:
Sentence1: scales are used for protection by scaled animals. 
Sentence2: Fish are covered with protection.
answer:

protection