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: Heterotrophs get food by eating other living things. 
Sentence2: fish eat other living things.

A: living
****
Q: Sentence1: Microbes are also called bacteria or microorganisms. 
Sentence2: Disease-causing bacteria have a negative impact on the body.

A: bacteria
****
Q: Sentence1: If thermal pollution is severe, then the entire aquatic ecosystem can be destroyed. 
Sentence2: Pesticides can cause entire ecosystems to be destroyed.

A:
destroyed
****