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.
--------
Question: Sentence1: Herbs are medicines and aids. 
Sentence2: herbs are used for curing people when they are sick.

Answer: Herbs


Question: Sentence1: a fire requires oxygen to burn. 
Sentence2: Oxygen has  eight protons and eight electrons.

Answer: oxygen


Question: Sentence1: a thermometer is used to measure temperature. 
Sentence2: Greater temperature means faster moving particles.

Answer:
temperature