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: All monkeys are mammals. 
Sentence2: monkeys conserve body heat with their hair or fur.
[A]: monkeys


[Q]: Sentence1: heating an egg causes a chemical reaction in the egg. 
Sentence2: Insects hatch from eggs.
[A]: egg


[Q]: Sentence1: Nephrons are the structural and functional units of the kidneys. 
Sentence2: things that have a glomerulus are the structural units of the kidneys.
[A]:
kidneys