Logic Riddles

Question: Using 3 periods (.) and 1 question mark (?) make this a logical and grammatically correct sentence:

"That that is is that that is not is not is that it it is"

Question: In a marble hall as white as milk, Lined with skin as soft as silk, Within a fountain crystal clear, A golden orb does appear, There are no doors to this stronghold, Yet thieves break in and steal the gold. What am I?

Question: A man looks out to a boat full of people But there's not a single person on board. How is this possible?

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?

Question: You are in a car with some helium balloons and hit the gas. While you accelerate, which way does the balloon move?