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.

Example Input: Sentence1: Carbon cycles quickly between organisms and the atmosphere. 
Sentence2: the atmosphere is essential to all living organisms.
Example Output: organisms

Example Input: Sentence1: Amphibians have permeable skin that easily absorbs substances from the environment. 
Sentence2: permeable skin easily absorbs air to breathe through.
Example Output: absorbs

Example Input: Sentence1: All insects have heads, abdomens, and thoraxes, antennae, six legs, and wings. 
Sentence2: All insects have wings that are part of the exoskeleton.
Example Output:
All