TASK DEFINITION: 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.
PROBLEM: Sentence1: For example, insulin is a protein hormone. 
Sentence2: Insulin is produced in a part of the cell called the ribosome.

SOLUTION: insulin

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

SOLUTION: small

PROBLEM: Sentence1: Most crabs are scavengers, such as the typical hermit crab . 
Sentence2: some scavengers use the shells of dead snails for homes.

SOLUTION:
scavengers