2013年专四真题dictation

What Are Dreams for?
One theory is that we dream to release the deep ,secret desires. Another theory is that dreams allow us to solve problems that we can't solve in real life. We go to sleep with a problem and wake up with the solution. If you believe that your dreams are important, then analyzing them may help you to focus on the problem and help you to find the solution. The modern image is that dreams are the brain's way of cleaning up the computer's hard disk .Dreams organize the events of the day into folders and delete, what is not needed.