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.

[EX Q]: Sentence1: Clouds are one form of condensation. 
Sentence2: Clouds are one form of changing from a gas into a liquid by reducing heat energy.
[EX A]: Clouds

[EX Q]: Sentence1: Methane gas is a produced by rotting compost, trash, and human waste. 
Sentence2: Methane gas can be produced by Slime molds.
[EX A]: Methane

[EX Q]: Sentence1: Some species of reptiles can go several weeks between meals. 
Sentence2: Crocodiles and gharials are two of the 446 reptile species found.
[EX A]:
reptiles