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: Combustion generates toxic fumes. 
Sentence2: High temperatures can cause toxic fumes.

SOLUTION: fumes

PROBLEM: Sentence1: Mammalian predators include the coyote and bobcat. 
Sentence2: a coyote's teeth is important for digestion.

SOLUTION: coyote

PROBLEM: Sentence1: Frogs are neat, Frogs are cool. 
Sentence2: tadpoles become neat and cool.

SOLUTION:
cool