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: Plants use unsaturated fatty acids to store energy. 
Sentence2: Plants and fish contain fatty acids.
[EX A]: Plants

[EX Q]: Sentence1: the emission of sulfur dioxide causes acid rain. 
Sentence2: Sulfur dioxide emissions causes soil nutrients to be leached away.
[EX A]: dioxide

[EX Q]: Sentence1: Lung cancer is the Godzilla of cancers. 
Sentence2: the godzilla of cancers is most often caused by exposure to tobacco smoke.
[EX A]:
Godzilla