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: hurricanes convert heat energy into mechanical energy. 
Sentence2: Hurricanes use heat to move objects.
[A]: hurricanes


[Q]: Sentence1: All frogs are amphibians. 
Sentence2: frogs have permeable skin that easily absorbs substances from the environment.
[A]: frogs


[Q]: Sentence1: Water is the most important nutrient for animals and humans. 
Sentence2: An animal requires water for survival.
[A]:
Water