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: a switch is used to start the flow of current in an electrical circuit. 
Sentence2: The flow of electrical current powers a light bulb.
[EX A]: current

[EX Q]: Sentence1: an earthquake causes the ground to shake. 
Sentence2: A number of buildings in Istanbul also were damaged in the earthquake.
[EX A]: earthquake

[EX Q]: Sentence1: Blood type is important for medical reasons. 
Sentence2: Medical treatment is overseen by medical personnel.
[EX A]:
medical