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: the ovaries are used in reproduction. 
Sentence2: Egg released by the ovary.
[A]: ovaries


[Q]: Sentence1: Some trees are maples. 
Sentence2: planting maples has a positive impact on an ecosystem.
[A]: maples


[Q]: Sentence1: Other lakes formed throughout the region caused by stream blockages. 
Sentence2: Damming a river results in stream blockages.
[A]:
blockages