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: Plants use unsaturated fatty acids to store energy. 
Sentence2: Plants and fish contain fatty acids.

SOLUTION: Plants

PROBLEM: Sentence1: Aquatic animals are adapted to living within certain salinity ranges. 
Sentence2: Animals adapted to living within certain salinity ranges require great amounts of water to survive.

SOLUTION: adapted

PROBLEM: Sentence1: Basically, heat is energy. 
Sentence2: All chemical reactions require heat to get started.

SOLUTION:
heat