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: Weather Clear weather usually means good visibility. 
Sentence2: High pressure systems can cause good visibility.
[EX A]: good

[EX Q]: Sentence1: cell division often causes growth. 
Sentence2: Cell division leads to reproduction.
[EX A]: cell

[EX Q]: Sentence1: Thus, touching the head of another person, threatens the well being of that person. 
Sentence2: Bacteria may spread directly by touching a person's head.
[EX A]:
head