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.

Sentence1: looking at bright objects has a negative impact on the eyes. 
Sentence2: Looking at bright objects have a negative impact on the retina.
bright

Sentence1: Cells are the units of function in living things. 
Sentence2: living things cannot survive without oxygen.
living

Sentence1: Soon a chorus of howling coyotes join in and the whole area reverberates with noise. 
Sentence2: reverberating noise is used to warn other wolves by wolves.

noise