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.

Sentence1: Heterotrophs get food by eating other living things. 
Sentence2: fish eat other living things.
living

Sentence1: Without light there is no sense of vision. 
Sentence2: Glass causes a sense of vision.
sense

Sentence1: Reptiles are a class of tetrapod vertebrates that produce amniotic eggs. 
Sentence2: Reptiles are a class of tetrapod vertebrates that lay shelled eggs.

Reptiles