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.

[Q]: Sentence1: smell is used for finding food by some animals. 
Sentence2: Food includes small rodents and birds.
[A]: food


[Q]: Sentence1: protein is used to repair cells by the human body. 
Sentence2: Meat, fish and chicken are rich sources of protein.
[A]: protein


[Q]: Sentence1: Nitrogenous wastes leave the body in the urine. 
Sentence2: nitrogenous wastes are excreted in urine.
[A]:
Nitrogenous