Choose the correct options

1. Duration of a perfect sleep.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].
2. It is possible to study in a dream.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].
3. Recurring dreams.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].
4. Why you can't get enough sleep on weekends.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].
5. How to cheer up in 15 minutes.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].
6. The reason of nightmares.
   [Speaker A|Speaker B|Speaker C|Speaker D|Speaker E|Nobody].