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: All lizards are reptiles. 
Sentence2: Lizards are tetrapod vertebrates that produce amniotic eggs.
[A]: lizards


[Q]: Sentence1: wind is used for producing electricity. 
Sentence2: Wind is caused because of pressure differences in the atmosphere.
[A]:
wind