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: high pressure systems cause clear weather. 
Sentence2: Weather Clear weather usually means good visibility.
Example Output: clear

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: Producers make food from inorganic molecules. 
Sentence2: If the plant is green, it is a producer.
Example Output:
Producers