Definition: 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.
Input: Sentence1: a planet rotating causes cycles of day and night on that planet. 
Sentence2: Our bodies and senses adjust to the cycle of day and night so that we may work in the day and sleep at night.

cycles