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: the ovaries are used in reproduction. 
Sentence2: Egg released by the ovary.
ovaries

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

Sentence1: Very often their only metal object in the house is a cooking pot or a knife. 
Sentence2: sharpening a knife causes it to change shape.

knife