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

SOLUTION: LED

PROBLEM: Sentence1: Some herbivores have more than one stomach. 
Sentence2: Camels are an herbivore.

SOLUTION: herbivores

PROBLEM: Sentence1: sunlight and rain can cause a rainbow. 
Sentence2: Rainbows are very pretty.

SOLUTION:
rainbow