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: Contact with infected blood, contaminated needles. 
Sentence2: scraping oneself on an infected needle may cause infection.

SOLUTION: infected

PROBLEM: Sentence1: a rainbow is formed by refraction of light by separating light into all different colors. 
Sentence2: Rainbows form when raindrops refract sunlight.

SOLUTION: refraction

PROBLEM: Sentence1: Cuticle helps prevent water loss, abrasions, infections, and damage from toxins. 
Sentence2: For example, silica aerogels affect the entire lipid layer on the insect cuticle.

SOLUTION:
Cuticle