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.

Sentence1: Dinosaur bones, like many other artifacts, are fossilized. 
Sentence2: radioactive dating is used to determine the age of dinosaur bones.
Dinosaur

Sentence1: Parasites are organisms that live off a host. 
Sentence2: roundworms may be free-living or live off a host.
host

Sentence1: Pathogens : a few types of bacteria in food are responsible for causing illness and are referred  to as pathogens. 
Sentence2: Some types of bacteria in food can cause disease.

bacteria