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.

[EX Q]: Sentence1: Every photograph is produced by a camera. 
Sentence2: Photographers record images.
[EX A]: photograph

[EX Q]: 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.
[EX A]: Ions

[EX Q]: Sentence1: Bioterrorism is the intentional release or spread of agents of disease. 
Sentence2: Variola major, the virus that causes smallpox, is considered a potential bioterrorism agent.
[EX A]:
agents