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: Cells are the microscopic building blocks of organisms. 
Sentence2: proteins are the building blocks of organisms.
answer:
organisms


question:
Sentence1: Echinoderms use pheromones to communicate with each other. 
Sentence2: Echinoderms are known for their round symmetry.
answer:
Echinoderms


question:
Sentence1: dropping an object into water causes vibrations in the water. 
Sentence2: By it's nature, a vibration is a frequency wave .
answer:

vibrations