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: creating wood-free paper does not require cutting down trees. 
Sentence2: creating printed media requires cutting down trees.

SOLUTION: creating

PROBLEM: Sentence1: Protozoa make humans sick when they become human parasites. 
Sentence2: paramecium are single celled animals that make humans sick when they become human parasites.

SOLUTION: become

PROBLEM: Sentence1: if food is not immediately used by the body for energy then that food will be stored for future use. 
Sentence2: if food is not immediately used for energy then that food will be converted into fat.

SOLUTION:
energy