What is black when it's clean and white when it's dirty?

Who has 13 hearts but no organs?

What has legs but doesn't walk?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?

What is the only question you can't answer yes too?

What has a bottom at the top?

What has an eye but can not see?

What's not alive but can die?

What has a neck but no head?

What has many keys but can't open a single lock?

What's the only room from which no one can enter or leave?

What 4 letter word starts with E and ends with E?

What has teeth but Cannot bite?