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.

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

Sentence1: Introns are regions that do not code for proteins. 
Sentence2: regions that do not code for proteins are removed by RNA splicing.
code

Sentence1: Powerful microscopes are used to see the chips. 
Sentence2: chips can be seen up close with optical tools.

chips