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: Homogeneous mixtures are called solutions. 
Sentence2: A homogenous mixture is formed when one substance dissolves in another.

A: Homogeneous
****
Q: Sentence1: protein is used to repair cells by the human body. 
Sentence2: Meat, fish and chicken are rich sources of protein.

A: protein
****
Q: Sentence1: changes in the pH of soil can cause plants to die. 
Sentence2: sulfur can cause plants to die.

A:
cause
****