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: pathogens can cause disease. 
Sentence2: pathogens affects the immune system.
[EX A]: pathogens

[EX Q]: Sentence1: Acid rain is precipitation which pH is 5.7 or lower. 
Sentence2: gases from burning coal causes precipitation which pH is 5.7 or lower.
[EX A]: 5

[EX Q]: Sentence1: Schwinn bikes have carried many TWW'ers to the podium time and time again. 
Sentence2: pushing on the pedals of a Schwinn causes it to move.
[EX A]:
Schwinn