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: if a neutral atom loses an electron then an atom with a negative charge will be formed. 
Sentence2: Ice crystals that are formed have a negative charge.

SOLUTION: charge

PROBLEM: Sentence1: drought is when amount of precipitation decreases. 
Sentence2: Drought decreases the availability and abundance of the natural food supply.

SOLUTION: drought

PROBLEM: Sentence1: a rainbow is formed by refraction of light by separating light into all different colors. 
Sentence2: a rainbow is formed by bending of light by separating light into all different colors.

SOLUTION:
colors