问题 问答题 简答题

我国如何对环境空气质量进行评价和分级?

答案

参考答案:我国目前主要使用空气质量指数(AQI)对环境空气质量进行评价和分级,在AQI指数大于50时,空气质量分指数最大的污染物为首要污染物。若空气质量分指数最大的污染物为两项或两项以上时,并列为首要污染物。首要污染物的选取方法与API指数基本相同,但是评价因子由三项(二氧化硫、二氧化氮和PM10)变为七项:二氧化硫、二氧化氮、PM10、一氧化碳、臭氧(1小时最大值)、臭氧(8小时均值最大值)和PM2.5。

单项选择题
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     You may be surprised to learn that one of the best steps you can take to protect your health is to step outside

and spend some time in the grass, dirt and water.

     Our ancestors enjoyed the healing power of nature, and now scientists are starting to catch up. According

to research in recent years, just having a view of nature has been shown to improve hospital patients' recovery

and reduce illness rates among office workers. Also, exposure (曝露) to wildlife, horseback riding, hiking,

camping and farms can be helpful for a variety of health conditions in adults and children.

     Much of this type of research is focusing on children, and in fact an entire movement has quickly developed

to connect kids with the healing power of nature.

     Obesity (肥胖). Rates of childhood obesity have grown sharply in recent years, and this is partly because of

reduced outdoor activity time. Increasing the time students spend learning about nature, both in and outside the

classroom, would help solve this problem. Such lessons are often more attractive for students and often lead

them to become more active outside.

     Attention deficit hyperactivity disorder (ADHD) (注意力缺失症). Exposure to ordinary natural settings (环

境) in the course of common after-school and weekend activities may be effective in reducing attention deficit

symptoms in children. Participation in green activities-such as nature walks-helped ADHD patients from a wide

range of backgrounds to stay focused and complete tasks.

     Stress. Access to nature, even houseplants, can help children cope with stress.

     Depression and seasonal emotional disorder. Major depression requires medical treatment, but physical

activity, especially outdoors, can help ease symptoms. For your average case of winter blues, experts suggest

spending time outside every day and, if possible, taking the family to a sunny vacation spot in mid-winter.

     Experts emphasize that you needn't go to wilderness preserves to enjoy nature's benefits-simply walking in

a city park or growing in a rooftop garden can make a difference.

1. It can be inferred from the first two paragraphs that _____.

A. ancient people were not familiar with the healing power of nature

B. modern people are not familiar with the healing power of nature

C. the healing power of nature works better on children

D. the healing power of nature works better on office workers

2. According to Para 4, lessons about nature _____.

A. should engage parents in them

B. should take place outdoors

C. are used widely at schools

D. are liked by students

3. Exposure to green areas in neighborhoods can _____.

A. improve children's skills at learning

B. help reduce ADHD symptoms

C. treat major depression

D. cure winter blues

4. What can be inferred from the last paragraph?

A. You can only enjoy nature's benefits in the wilderness.

B. A common natural setting is beneficial to your health.

C. A city park and a rooftop garden have different benefits.

D. Too many people in the wilderness will reduce the benefits of nature.