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: With a spatula, fold in flour mixture. 
Sentence2: a sifter is used for separating flour.

SOLUTION: flour

PROBLEM: Sentence1: For instance, glucose is a sugar. 
Sentence2: insulin helps cells take up sugar from the blood.

SOLUTION: sugar

PROBLEM: Sentence1: a pan is used for cooking food by heating food in it on a stove. 
Sentence2: a pan is used for cooking food by putting it over fire.

SOLUTION:
cooking