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: Mating is generally preceded by courtship. 
Sentence2: Mating is generally similar across species.
[EX A]: Mating

[EX Q]: Sentence1: With a spatula, fold in flour mixture. 
Sentence2: a sifter is used for separating flour.
[EX A]: flour

[EX Q]: Sentence1: Adolescents are in the school leaving age. 
Sentence2: The school leaving age is a time of significant mental, emotional, and social changes.
[EX A]:
age