No one country owns the sea
The Antilles are a series of islands in the Caribbean, no one country owns them. Each island is a country.
China owns itself!
They are called arborists.
Germany owns the Lamborghini company
Nobody "owns" Switzerland, it is an independent country.
A group of European countries owns Airbus.
No country does.
Philippines is country...no country owns them
It really depends on what country owns the nuclear weapons, if your country owns them, then the only thing you have to worry about is that it will go off by accident (Completely unlikely). But if it is an enemy country that owns them you have to watch out for nuclear attacks.
No one owns amity square. EDIT: This is in fact not at all true, the person who owns the Pokemon Mansion, you know him? Well he's the Owner of Amity Square.
Madison Square Garden is owned by Cablevision