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: Cell death occurs by activation of cell death genes. 
Sentence2: Aging is associated with the activation of certain genes.
[EX A]: activation

[EX Q]: Sentence1: Most people know that the Venus Flytrap is a carnivorous plant. 
Sentence2: The Venus Flytrap has specialized reproductive organs.
[EX A]: Flytrap

[EX Q]: Sentence1: the ovaries are used in reproduction. 
Sentence2: Humans are produced by two-parent reproduction.
[EX A]:
reproduction