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: Many birds perform elaborate courtship dances. 
Sentence2: Many birds perform dances before they mate.
[EX A]: Many

[EX Q]: Sentence1: Most soil nutrients are cations. 
Sentence2: decomposition increases the amount of cations in the soil.
[EX A]: cations

[EX Q]: Sentence1: The agent responsible for the push or pull is the magnetic force . 
Sentence2: Force can cause objects to repel each other.
[EX A]:
force