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: Sex hormones are chemical messengers that control sexual development and reproduction. 
Sentence2: Androgens are male sex hormones.
[EX A]: Sex

[EX Q]: Sentence1: Fertilization occurs naturally in the fallopian tubes. 
Sentence2: fertilization is used for reproduction.
[EX A]: Fertilization

[EX Q]: Sentence1: the movement of tectonic plates causes volcanic eruptions. 
Sentence2: Earthquakes and volcanic eruptions can cause tsunamis.
[EX A]:
eruptions