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: wiring requires an electrical conductor. 
Sentence2: Gold is an excellent conductor of electricity.
Example Output: conductor

Example Input: Sentence1: All frogs are amphibians. 
Sentence2: frogs have permeable skin that easily absorbs substances from the environment.
Example Output: frogs

Example Input: Sentence1: Some viruses can cause cancer. 
Sentence2: Oncogenic viruses are viruses that are linked to cancer.
Example Output:
cancer