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: 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: a magnet moving in a coil of copper wire can cause an electric current. 
Sentence2: An electric current forms when a magnet is run through an induction coil.
[EX A]: current

[EX Q]: Sentence1: Bone is less flexible than cartilage but stronger. 
Sentence2: Sharks have a cartilage skeleton.
[EX A]:
cartilage