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

[EX Q]: Sentence1: Cancer is a disease in which cells divide out of control. 
Sentence2: Cancer is a disease in which cells grow and divide rapidly.
[EX A]: Cancer

[EX Q]: Sentence1: water vapor condensing in clouds causes rain. 
Sentence2: Water vapors turn into clouds and rain when it's cool.
[EX A]:
rain