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: Dinosaur bones, like many other artifacts, are fossilized. 
Sentence2: radioactive dating is used to determine the age of dinosaur bones.

SOLUTION: Dinosaur

PROBLEM: Sentence1: Cnidarians are invertebrates such as jellyfish and corals. 
Sentence2: Jellyfish and corals are radial, tentacled animals that live mostly in the seas.

SOLUTION: corals

PROBLEM: Sentence1: When it is tilted away from the sun, it is winter. 
Sentence2: The side of the earth receiving less energy from the sun is experiencing winter.

SOLUTION:
winter