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: a camera is used for recording images. 
Sentence2: a camera is used for recording binary.
[A]: camera


[Q]: Sentence1: An astronaut is a scientist who is a space explorer. 
Sentence2: Space explorers require preserved food for long flights.
[A]: explorer


[Q]: Sentence1: eating something that contains pollutants has a negative impact on an organism 's survival. 
Sentence2: Eating something that contains pollutants can kill directly and selectively.
[A]:
contains