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.

Sentence1: a battery converts chemical energy into electrical energy. 
Sentence2: A battery produces a flow of electrons.
battery

Sentence1: Earthquakes are natural disasters. 
Sentence2: earthquakes can cause animals to leave an environment.
Earthquakes

Sentence1: Any infection can cause death. 
Sentence2: scraping oneself can cause death.

death