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: All photos are digital images.
Sentence2: satellites are used to take photos from space.
[EX A]: photos

[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: Bacteria may spread directly from one person to another.
Sentence2: Streptococcus can be spread directly from one person to another.
[EX A]:
another