根据短文内容简要回答下面的问题．

Life is hard．And junior middle school students have every reason tosay so．Recently，Zhejiang did a survey of young people's mental（精神的）health．It found that junior middle school students in Zhejiang feel thebiggest pressure from school among teensgers．Besides，48.8% of middleschool students show signs of mental health problems．

What are students worried about？

"First，the class ranking（排名）after exams．Second，being unableto reach their parents' expectation，"the Youth Time reported．This is not only true with Chinese students．The experts in America recently did a similar survey．The resultsare surprising：In the US，teenagers have a higher level of stress than

adults．For them，one of the big reasons for stress is also schoolwork．

What can we do to help？

*Be sure to have an active life．

*Sleep for 9﹣10hours a day．

*Find someone to exercise with every day．

71．What kind of survey did people do in Zhejiang recently？

　　

72．According to the passage，how many things do the Chinese students

worry about？

　　

73．Do the students in America also have stress in schoolwork

　　

74．Who have a higher level of stress in America，teenagers or adults？

　　

75．How many hours should students sleep a day in order to reduce theirstress？