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: Sperm pass out of the body through the urethra. 
Sentence2: Sperm travel from the testicles through the vas deferens to the seminal vesicles and the prostate.
Example Output: Sperm

Example Input: Sentence1: Climate refers to weather over a long period of time. 
Sentence2: weather is generally described in terms of temperature and moisture.
Example Output: long

Example Input: Sentence1: Objects displace their volume in a fluid. 
Sentence2: The amount that a fluid is displaced by an object can describe the size of the object.
Example Output:
Objects