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: Battery electricity comes conversion.
battery

Sentence1: the moon revolving around the Earth causes the phases of the moon. 
Sentence2: Lets start our discussion of the Moon's phases with the New Moon phase.
phases

Sentence1: microbial fuel cells convert chemical energy into electrical energy. 
Sentence2: Food is chemical energy.

chemical