Long Riddles and Answers

Question: You are in a brick cube. Now way in and no way out. There is only a table and a mirror. How do you get out?

Question: When the answer I give is yes, it is no, and when the answer I give is no, it is yes. What is the question?

Question: What word begins with letter H, but add it with W and it becomes another word yet pronounced just the same?

Question: I am alive yet not alive. I can fly yet always on the ground. I am delicate yet can lift tonnes. What am I?

Question: I always murmur but never talk, i always run but never walk, and I have a bed but I don't sleep. What am I?