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: the ovaries are used in reproduction. 
Sentence2: Unlike most female animals, which have two functioning ovaries, the chicken usually has only one.

SOLUTION: ovaries

PROBLEM: Sentence1: Fission is a type of reproduction, but a baby is the result of sexual reproduction. 
Sentence2: the fallopian tubes are used to make babies.

SOLUTION: baby

PROBLEM: Sentence1: Fungi have special structures for penetrating a host. 
Sentence2: bacteria cause disease in hosts.

SOLUTION:
host