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: Gravity is a force that pulls on things. 
Sentence2: A force that pulls on things pulls objects towards planets.

A: force
****
Q: Sentence1: Light is the visible form of electromagnetic energy. 
Sentence2: Electromagnetic energy enters the eye through an opening called the pupil.

A: electromagnetic
****
Q: Sentence1: the looseness of soil has a positive impact on a plant 's roots' growth in that soil. 
Sentence2: looseness of soil improves soil structure.

A:
looseness
****