Answer:
What is it that given one, you'll have either two or none?
It has the biggest wall and is also used when drinking tea.
Four kings of whom I am one lord. Often on deck but never on board. Though I have a large heart, I am always seen at war. During which I always wear a suit, but never a suit of armor. Who or what am I?
When will water stop running down hill?
No matter how little or how much you use me, you change me every month. What am I?
What language does a billboard speak?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?