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 light bulb is used for seeing in the dark. 
Sentence2: light is required for seeing.

SOLUTION: seeing

PROBLEM: Sentence1: Ribosomes are structures in the cytoplasm where proteins are made. 
Sentence2: prokaryotes can make proteins.

SOLUTION: made

PROBLEM: Sentence1: recycling has a positive impact on the environment. 
Sentence2: Reuse of materials has a positive impact on the environment.

SOLUTION:
environment