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: if an object in a fluid is more dense than that fluid then that object will sink in that fluid because of gravity. 
Sentence2: Most seeds are more dense than water.

SOLUTION: dense

PROBLEM: Sentence1: wind is used for producing electricity. 
Sentence2: Winds are caused by pressure differences.

SOLUTION: wind

PROBLEM: Sentence1: natural disasters can cause animals to leave an environment. 
Sentence2: If the property is damaged by a fire, natural disaster.

SOLUTION:
disasters