听下面一段独白，回答以下小题。
【小题1】What can be affected certainly if teenagers lack sleep?

A．Their spirits.

B．Their long-term health.

C．Their academic performance.

【小题2】What is to blame for teenagers lacking sleep?

A．Poor diet.

B．Lack of exercise.

C．Too much entertainment.

【小题3】How can teenagers fall asleep easier?

A．Reading a book before sleeping.

B．Listening to music before sleeping.

C．Drinking hot chocolate before sleeping.

【小题4】What does the speaker suggest schools do?

A．Offer art classes.

B．Shorten the school day.

C．Start and end the school day later.