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: a wildfire changes an ecosystem drastically. 
Sentence2: Forest fires change an ecosystem drastically.

SOLUTION: changes

PROBLEM: Sentence1: Light source is an ultra-bright, unbreakable LED Bulb. 
Sentence2: LEDs convert electricity into light and heat energy.

SOLUTION: LED

PROBLEM: Sentence1: Organisms cluster around hydrothermal vents in the ocean floor. 
Sentence2: Organisms cluster around hot water inside cracks in the ocean floor.

SOLUTION:
Organisms