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.

[EX Q]: Sentence1: lightning can cause a forest fire. 
Sentence2: Lightning can cause a natural cycle in forests.
[EX A]: lightning

[EX Q]: Sentence1: Temperature Scales Temperature is the energy of vibration. 
Sentence2: a thermometer is used to measure energy of vibration.
[EX A]: energy

[EX Q]: Sentence1: Male dogs use pheromones in urine to mark their territory. 
Sentence2: Male dogs use semiochemicals in urine to mark their territory.
[EX A]:
Male