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: Capillaries are microscopic vessels. 
Sentence2: Lymph is a fluid that leaks out of microscopic vessels into spaces between cells.
[A]: microscopic


[Q]: Sentence1: when electricity flows to a light bulb , the light bulb will turn on. 
Sentence2: water pumps can turn on light bulbs.
[A]: bulb


[Q]: Sentence1: Fire is a natural cycle in forests. 
Sentence2: Lightning can cause a natural cycle in forests.
[A]:
cycle