Part 1. Definition
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.
Part 2. Example
Sentence1: pesticides cause pollution. 
Sentence2: pollution can harm animals.
Answer: pollution.
Explanation: The word "pollution" is common to Sentence1 and Sentence2. So, it's a good answer.
Part 3. Exercise
Sentence1: Bacteria thrive in higher temperatures. 
Sentence2: Higher temperatures cause food to spoil.
Answer:
higher