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: cold fronts cause thunderstorms as they pass by. 
Sentence2: Thunderstorms create havoc.

SOLUTION: thunderstorms

PROBLEM: Sentence1: All oaks are trees. 
Sentence2: Cutting down oaks has a negative impact on an ecosystem.

SOLUTION: oaks

PROBLEM: Sentence1: a telephone is used for communication by humans over long distances. 
Sentence2: Telephones are used to share ideas, thoughts and views by humans over long distances.

SOLUTION:
distances