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: Streams may start with runoff or water seeping out of a spring. 
Sentence2: streams may start with runoff or h2o seeping out of a spring.

Answer: Streams


Question: Sentence1: a fire requires oxygen to burn. 
Sentence2: If the oxygen is removed, the fire is smothered.

Answer: oxygen


Question: Sentence1: When earthquakes occur near cities of any size, the potential for damage is great. 
Sentence2: A seismograph is used for measuring the size of the damage done by an occurrence.

Answer:
damage