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: Asbestos is a dangerous carcinogen. 
Sentence2: Asbestos causes cancer.

SOLUTION: Asbestos

PROBLEM: Sentence1: Marine dolphins are endangered by fishing nets, speedboats, and pollution. 
Sentence2: dolphins live mainly in shallow coastal waters.

SOLUTION: dolphins

PROBLEM: Sentence1: a refrigerator is used for keeping food fresh for a long period of time. 
Sentence2: Fresh food is good.

SOLUTION:
fresh