TASK DEFINITION: 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.
PROBLEM: Sentence1: Ions are atoms or groups of atoms that carry a positive or negative electrical charge. 
Sentence2: An ion is formed after a neutral atom loses an electron.

SOLUTION: Ions

PROBLEM: Sentence1: Digestion is the process of breaking down food into components the body can absorb. 
Sentence2: Saliva starts to break down the food.

SOLUTION: breaking

PROBLEM: Sentence1: pathogens can cause disease. 
Sentence2: If the parasite causes harm, it is a pathogen.

SOLUTION:
pathogens