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: For example, in the sentence The rain destroyed the crops , The rain is the subject. 
Sentence2: If weather is stormy then there is a chance of destroyed crops.

SOLUTION: crops

PROBLEM: Sentence1: Female monotremes lack a uterus and vagina. 
Sentence2: Babies are normally delivered from the uterus through the vagina.

SOLUTION: uterus

PROBLEM: Sentence1: Birds move their wings using muscles in the chest. 
Sentence2: Birds use muscles in the chest to fly.

SOLUTION:
Birds