Good Riddles

Question: Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

Question: I have more shoes than anybody,
but less feet than everyone.
I am met in the morning,
but departed in the night.
I may shake as if I'm angry,
but I won't bite.

What am I?

Question: I open to close but I close to open.
I'm surrounded by water but I'm never soaking.

What am I?

Question: You have a flashlight that takes 2 working batteries. You have 8 batteries but only 4 of them work.

What is the fewest number of pairs you need to test to guarantee you can get the flashlight on?

Question: A man goes out drinking every night, returning to his home early every morning. No matter how much he drinks, he never gets a hangover. This drink is very well known, but is rarely consumed, served warm and taken straight from its source. The man is a sucker for a free drink, especially since he can't live without it.

What is his favorite drink?