Good Riddles

Question: I wasn't born a horse,
and I never fly.
Yet sometimes I still soar,
right into the sky.
I often contain breath,
and yet I never die.
Sometimes I am torn,
but I never sigh.
Often, with ambition, I aspire,
and go till I can go no higher.
Then, like many men, so great,
I sink into a low state.
What am I?

Question: Tom and Joe want to sit behind each other in class and the teacher arranges them so they are both happy.

How did the teacher do so?

Question: If you have a cake, how many pieces of cake can you form with 3 straight cuts?

Question: When warm my house expands and when cold it contracts,
I am vital to a certain type of pact.

What am I?

Question: A very important man is about to take a trip to Iceland. He is awoken in the middle of the night by his security guard the night before he is supposed to leave. His guard tells him he needs to take a boat rather than a plane, because he just dreamt that the plane was going to crash. The guard leaves because it's the end of his shift.

The man listens to his guard and takes a boat. Soon after arriving in Iceland he hears that the plane he was supposed to go on crashed. When he arrives home he fires his guard.

Why?