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: Some mollusks are nearly microscopic. 
Sentence2: Some squids are nearly microscopic.

A: Some
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Q: Sentence1: Sperm had to swim from male to female reproductive organs for fertilization. 
Sentence2: If fertilized, the egg implants itself in the uterus.

A: fertilization
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Q: Sentence1: DNA contains genetic instructions for proteins, and RNA helps assemble the proteins. 
Sentence2: DNA contains genetic instructions for proteins, which is a product of evolution.

A:
DNA
****