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

Answer: Spikes


Question: Sentence1: Most bryophytes are small. 
Sentence2: Most in the same group as mosses are small.

Answer: small


Question: Sentence1: Roundworms may be free-living or parasitic. 
Sentence2: roundworms can harm their hosts.

Answer:
Roundworms