Fun Riddles

Question: I have Eighty-eight keys but cannot open a single door?

What am I?

Question: You fill up a bathtub with water and you have a teaspoon, tablespoon, and fourth cup. What is the fastest way to empty the bathtub?

Question: A five lettered word, I'm used to make bread.
Remove one letter and I'll burn you instead.
Remove two and do this to your stew.
Mix that around and a good drink we will brew.

Question: A man orders a coffee and finds a fly in it. He sends it back and gets another one. But he quickly discovers that they gave him the same coffee that had the fly in it.

How did he know?

Question: Whoever makes me can hear me, but nobody else can.

What am I?