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: Rainy clouds cause rain, and excess water vapor from clouds is the basis of rainbows. 
Sentence2: Condensation can lead to rain.

A: rain
****
Q: Sentence1: zinc has a positive impact on the healing of wounds. 
Sentence2: oysters have a positive impact on the healing of wounds.

A: has
****
Q: Sentence1: a radio converts electrical energy into vibrations. 
Sentence2: Ordinary hearing is the result of the stimulation of bones in the inner ear by means of vibration.

A:
vibrations
****