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: information in an organism 's chromosomes cause genetic traits to be passed down to that organism 's offspring. 
Sentence2: information in Man's chromosomes cause genetic traits to be passed down to offspring.
Example Output: chromosomes

Example Input: Sentence1: a flashlight requires a source of electricity to produce light. 
Sentence2: Flashlights provide the safest emergency lighting source.
Example Output: flashlight

Example Input: Sentence1: Antibodies are designed to bind with foreign proteins, called antigens. 
Sentence2: Antibodies are large, Y-shaped proteins designed to bind with foreign proteins.
Example Output:
bind