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: Interstellar space contains a plasma. 
Sentence2: interstellar space contains electrons, atoms, and stars.
[A]: Interstellar


[Q]: Sentence1: Skin color is another polygenic trait. 
Sentence2: Skin color is influenced by multiple genes.
[A]: Skin


[Q]: Sentence1: Another major type of wind is called a polar easterly. 
Sentence2: Unequal heating of Earth 's surface by the Sun causes polar easterlies.
[A]:
easterly