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.

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

A: erosion
****
Q: Sentence1: Sound vibrations can be compared to pond ripples. 
Sentence2: dropping an object into water causes pond ripples.

A: pond
****
Q: Sentence1: Sponges are filter feeders. 
Sentence2: Porifera are filter feeders.

A:
feeders
****