1. (2019高二上·靖远期末) 阅读理解

    Exercise is known to benefit people's mental health, but scientists recently discovered that too much exercise may have a negative effect on it.

    The researchers studied about 1.2 million people in the United States in 2013, 2015 and 2017. The participants, on average, experienced 3, 4 days of poor mental health each month. Those who did exercise experienced 1, 5 fewer days of poor mental health per month, compared to those who didn't exercise at all. The team found that people who exercised for 30 to 60 minutes three to five times a week had the best mental health, but those who exercised for more than three hours had worse mental health than those who didn't exercise at all.

    The scientists think that people who exercise so much may experience poorer mental health because that much exercise can be a sign of obsessive (强迫症患者) behaviors that have been associated with poor emotional and psychological outcomes. However, the only mental health disorder that the researchers looked at was depression.

    Among those who had been diagnosed with depression, people who did exercise experienced 3.75 fewer negative mental health days than those who did not, showing an ever greater difference, According to the Centers for Disease Control and Prevention. 7, 6 percent of people in the U.S. age 12 and over have depression. While all types of exercise appeared to help with mental health, cycling, gym-based exercise and team sports were the most beneficial.

    The team also looked at more specific factors, like education. People with a college education reported 17.8 percent fewer days of poor mental health than those without that level education Additionally, people in a healthy BMI (体重指数) range reported a 4 percent reduction in poor mental health days thin those whose BMIs were high. Even salary was a factor: compared to people with bower salaries, those with higher salaries experienced a 17 percent reduction in poor mental health days.

    The study showed that exercise can help with mental health, but that in some cases, limiting it may be necessary.

1. （1） What did the study find?

   A . People should do exercise three to five times a month. B . Too much exercise may affect people's mental health. C . The more exercise people do, the healthier body they have. D . People who do exercise have problems in mental health.
3. （2） Which of the following sports benefits peoples mental health most according to the text?

   A . Skiing. B . Football. C . Mountain climbing. D . Motorcycle racing.
5. （3） How many factors that affect mental health are mentioned in the text?

   A . Two. B . Three. C . Five. D . Four.
7. （4） What can we infer from the text?

   A . We must reduce our time of doing regular exercise. B . Most American children have mental health problems. C . Doing exercise reasonably is beneficial to relieving depression. D . The men who don't do exercise have the worst mental health.