Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

michelbach-le-bas is a commune.
michelbach-le-bas

panoplosaurus was an armored tank-like dinosaur from the upper cretaceous, living about 76–73 million years ago.
panoplosaurus

semen (pronounced "") is the fluid that comes out from the end of a man's penis when he has an orgasm (the height of sexual excitement) and ejaculates.

semen