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: Blood type is important for medical reasons. 
Sentence2: Type O is important for medical reasons.

SOLUTION: important

PROBLEM: Sentence1: Bird eggs have hard, calcium carbonate shells. 
Sentence2: The reproductive cells of a bird is a hard, calcium carbonate shell.

SOLUTION: calcium

PROBLEM: Sentence1: Platypus females lay their eggs in a burrow. 
Sentence2: When the eggs hatch, the hen leaves the nest site.

SOLUTION:
eggs