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: Fully cooking oysters kills the bacteria. 
Sentence2: Fully cooking oysters can prevent illness.

SOLUTION: Fully

PROBLEM: Sentence1: if fossils of a water animal or plant are found in a place then that place used to be covered by water in the past. 
Sentence2: Fossils of a water animal or plant are located in water-laid sediments.

SOLUTION: animal

PROBLEM: Sentence1: being burried under soil and mud changes peat into coal through extreme heat and pressure in a swamp over a long period of time. 
Sentence2: being buried under soil and mud changes plants into coal.

SOLUTION:
burried