instruction:
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.
question:
Sentence1: Many birds perform elaborate courtship dances. 
Sentence2: Many birds perform dances before they mate.
answer:
Many


question:
Sentence1: First, the bottle is calibrated with a graduated cylinder. 
Sentence2: calibration is performed with a cylinder.
answer:
calibrated


question:
Sentence1: boiling means change from a liquid into a gas by adding heat energy. 
Sentence2: For a smoother flavor, bring soup to a boil.
answer:

boiling