C. To encourage students to take part in discussions.

　　D. To advise students to choose proper majors.

　　C

　　It's common knowledge that there are many benefits to being fit, but one large new study found that skipping out on the gym is practically the worst thing you can do for your health. In fact, the study claims not exercising might be more harmful to your health than smoking.

　　New findings, published Friday in the journal JAMA Network Open, detail how researchers at the Cleveland Clinic studied 122,007 patients from 1991 to 2014, putting them under treadmill (跑步机) testing and later recording death rates. Researchers found a clear connection between a longer, healthier life and high levels of exercise. The report calls for health care professionals to encourage patients to achieve and continue a strong and healthy fitness routine.

　　Although it is widely understood that an active lifestyle can lead to a healthy life, the study concludes that a lifestyle which involves much sitting but little activity is equal to having a major disease and the simplest cure is exercise.

　　Dr Wael Jaber, co-author of the study, called the results totally surprising. "Being unfit on a treadmill or in an exercise stress test has a worse prognosis (病情预断), as far as death, than being a smoker or suffering from high blood pressure," Jaber told CNN. "We've never seen something as noticeable as this and as objective as this."

　　The study also took a look at the risk of being overactive and found that extreme exercisers do not face higher risk of death: the research found that the more a person exercises the lower their death rates.

7. Which of the following best explains "skipping out on" in paragraph 1?

　　A. keeping away from B. running in C. jumping out of D. smoking inside

8. What do we know from the new findings?

　　A. An active lifestyle can lead to a healthy life.

　　B. The simplest cure for a major disease is exercise.

　　C. A person unfit on a treadmill is less likely to die.

　　D. One's life span(长度) is related to the level of exercise.

9. What does Jaber think of the research results?

A. Impossible. B. Amusing. C. Unbelievable. D. Uncertain.