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: friction causes the temperature of an object to increase. 
Sentence2: Friction causes the temperature of a toy to increase.

SOLUTION: causes

PROBLEM: Sentence1: Carpools and vanpools can save time. 
Sentence2: vanpools decrease the amount of cars used to travel to a place.

SOLUTION: vanpools

PROBLEM: Sentence1: Mollusks reproduce sexually. 
Sentence2: some animals with shells reproduce sexually.

SOLUTION:
reproduce