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: zinc has a positive impact on the healing of wounds. 
Sentence2: oysters have a positive impact on the healing of wounds.
has

Sentence1: Digestion is the process of breaking down food into components the body can absorb. 
Sentence2: Saliva starts to break down the food.
breaking

Sentence1: Spikes are forceful the tidal waves of electric current. 
Sentence2: spikes come from tidal energy.

Spikes