Good Riddles

Question: Walk on the living, they don't even mumble.
But walk on the dead, they mutter and grumble.

What are they?

Question: You have two books. One of them is upside-down and the other is rotated so the top of the book is facing you.

What is the sum of the first page in each book?

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?

Question: Some use me, while others do not.
Some remember, while others have forgot.
For profit and gain I'm used expertly, I can't be picked off the ground or tossed in the sea.
Only gained through patience and time, can you unravel my rhyme?

Question: If you look at my face there won't be 13 any place.