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: Cancer is a disease in which cells divide out of control. 
Sentence2: Cancer is a disease in which cells grow and divide rapidly.

SOLUTION: Cancer

PROBLEM: Sentence1: Examples of gametes are ova and spermatozoa. 
Sentence2: fertilization of ova and spermatozoa produces a diploid zygote.

SOLUTION: ova

PROBLEM: Sentence1: Kidney failure may be treated with dialysis. 
Sentence2: Dialysis is the mechanical process of cleaning the blood.

SOLUTION:
dialysis