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

SOLUTION: sugar

PROBLEM: Sentence1: a pulley is used for lifting objects. 
Sentence2: Resistance exercises are weight-lifting exercises.

SOLUTION: lifting

PROBLEM: Sentence1: Fungi lack chlorophyll, so they cannot make food by photosynthesis as plants can. 
Sentence2: mushrooms lack chlorophyll, so they cannot make food by photosynthesis as plants can.

SOLUTION:
can