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.

[Q]: Sentence1: Nonmetal elements are far fewer in number. 
Sentence2: There are 17 nonmetals on the periodic table.
[A]: Nonmetal


[Q]: Sentence1: protein is used to repair cells by the human body. 
Sentence2: Meat, fish and chicken are rich sources of protein.
[A]: protein


[Q]: Sentence1: ultraviolet light causes sunburn. 
Sentence2: Ultraviolet light causes skin to become red and painful to the touch.
[A]:
causes