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: Some herbivores have more than one stomach. 
Sentence2: Camels are an herbivore.

SOLUTION: herbivores

PROBLEM: Sentence1: freezing means changing from a liquid into a solid by reducing heat energy. 
Sentence2: Water freezes into ice when cooled.

SOLUTION: freezing

PROBLEM: Sentence1: Interestingly, a squid is also a mollusk. 
Sentence2: Squid have a circulatory system with one or two hearts that pump blood.

SOLUTION:
squid