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: Coral reefs provide food and shelter to many ocean organisms. 
Sentence2: Coral Reefs Coral reefs are threatened.

SOLUTION: Coral

PROBLEM: Sentence1: burning fossil fuels increases the carbon in the atmosphere. 
Sentence2: Oil is one type of fossil fuel.

SOLUTION:
fossil