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: If there is sun, there is sunlight, there is day.
Sentence2: Energy enters ecosystems from the sun.
answer:
sun

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

question:
Sentence1: bacteria can cause people to become ill.
Sentence2: Properly and frequently washing hands when handling food helps eliminate bacteria.
answer:
bacteria