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: Ozone depletion results in higher levels of UV radiation reaching Earth. 
Sentence2: less ozone means more ultraviolet light.
[EX A]: Ozone

[EX Q]: Sentence1: Pregnancy is the carrying of one or more offspring from fertilization until birth. 
Sentence2: An elephant carries their offspring from fertilization until birth, 22 months later.
[EX A]: fertilization

[EX Q]: Sentence1: fanning a fire increases the oxygen near the fire. 
Sentence2: avoid winds to keep oxygen from the fire.
[EX A]:
oxygen