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: a seismometer is used to measure the strength or magnitude of an earthquake. 
Sentence2: Seismometer Calibration : Instructions on how to calibrate a homemade seismometer.

SOLUTION: seismometer

PROBLEM: Sentence1: if an object is made of a material then that object has the properties of that material. 
Sentence2: If an object is made of a drug, then that object has the properties of that drug.

SOLUTION: made

PROBLEM: Sentence1: Lung cancer is most often caused by exposure to tobacco smoke. 
Sentence2: Tobacco smoke contains tar.

SOLUTION:
smoke