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: wiring requires an electrical conductor. 
Sentence2: Gold is an excellent conductor of electricity.
[A]: conductor


[Q]: Sentence1: Plants exhibit phototropism, or growing toward a light source. 
Sentence2: Phototropism means growing toward the energy of light.
[A]: phototropism


[Q]: Sentence1: a battery converts chemical energy into electrical energy. 
Sentence2: Electricity is a powerful energy source.
[A]:
electrical