Logic Riddles

Question: Spell "Hard Water" using only 3 letters.

Question: What is in the middle of nowhere?

Question: You have 20 sick sheep, one dies. How many are left?

Question: Does England have a 4th of July?

Question: At the beginning of the first day of school there was a dead boy found inside of a classroom. They found 3 suspects: The janitor, the teacher and one of the boy's classmates. The janitor claims that he was just cleaning the room, the teacher said that she was computing her student's grades and the boy's classmate claims that he was listening to music.

Who committed the crime?