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: Mammalian predators include the coyote and bobcat. 
Sentence2: a coyote's teeth is important for digestion.
answer:
coyote


question:
Sentence1: Mutations are essential for evolution to occur. 
Sentence2: Genes are altered for evolution to occur.
answer:
evolution


question:
Sentence1: The gravitational pull of the major planets alters the orbital period from revolution to revolution. 
Sentence2: Gravitational pull causes alternative day cycles.
answer:

gravitational