题目内容：

听下面一段独白，回答以下小题。

1.What can be clearly affected if teenagers lack sleep?

A. Their spirits.    B. Their long-term health.    C. Their academic performance.

2.What is to blame for teenagers not getting enough sleep according to the speaker?

A. Poor diet.    B. Lack of exercise    C. Too much entertainment

3.What advice does the speaker give to teenagers who have trouble getting to sleep?

A. Listen to music.    B. Read a book.    C. Drink hot chocolate.

4.What does the speaker suggest schools should do?

A. Start lessons later.    B. Shorten the school day.    C. Offer classes in the evenings.