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: Protein Protein is needed for tissue maintenance and repair. 
Sentence2: protein repairs cells.

SOLUTION: Protein

PROBLEM: Sentence1: Mangoes are propagated vegetatively and by seeds. 
Sentence2: animals propagate mangoes.

SOLUTION: Mangoes

PROBLEM: Sentence1: a pesticide is used for protecting plants by killing insects. 
Sentence2: DDT is used for protecting plants by killing insects.

SOLUTION:
by