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: forming coal requires decaying vegetation. 
Sentence2: Forming fossil fuels requires decaying vegetation.

A: decaying
****
Q: Sentence1: Mad Cow disease is a concern. 
Sentence2: pathogens can cause Mad Cow.

A: Cow
****
Q: Sentence1: Blood pressure is highest in arteries and lowest in veins. 
Sentence2: Veins take blood to the heart.

A:
veins
****