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: An electric current is a flow of electric charge. 
Sentence2: a magnet moving in a coil of copper wire can cause a flow of electric charge.
[A]: charge


[Q]: Sentence1: Sex hormones are chemical messengers that control sexual development and reproduction. 
Sentence2: Androgens are male sex hormones.
[A]: Sex


[Q]: Sentence1: Lions live in social groups called prides. 
Sentence2: Chimpanzees live in social groups called communities.
[A]:
groups