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: Electrical currents cause magnetic fields. 
Sentence2: Electrical currents can cause objects to repel each other.
Example Output: Electrical

Example Input: Sentence1: rain causes erosion. 
Sentence2: Soil Erosion Soil erosion is what happens when soil is washed or blown away.
Example Output: erosion

Example Input: Sentence1: building housing developments usually requires replacing animal habitats. 
Sentence2: Replacing animal habitats skyrocketed around the facilities.
Example Output:
animal