本文讲述学生孙润发现自己视力下降很快，主要原因是看电子屏幕太多，我国政府已采取行动，要求学生每天进行两小时户外活动，教科书字体大一些，荧屏尽量减少蓝光，因为蓝光会杀死感光细胞。
   With her eyes always feeling tired as she prepared for an exam, 16-year-old Sun
Run went to the hospital with her parents in January. She was shocked when she found out that her eyesight dropped from 5.0 to 4.6. “A few of my friends have had the same experience,"Sun said.
    In fact, poor eyesight among Chinese students went up from 59.2% to 70. 6% in the first six months of 2020, according to the Ministry of Education. By 2050, half of the world's population will be nearsighted (近视的),according to a study published in the journal Ophthalmology. The main reason for this is that people's lifestyles have changed.They spend less time outdoors but more time looking at screens.
   To protect students' eyesight in China,the government(政府)has taken steps.In May 2020, the National Health Commission strongly required(要求)schools to make sure that students have at least two hours of outdoor activities a day. The Chinese government has worked out new requirements for school equipment that will take effect on March 1, 2022. For example, according to the requirements,the fontsize(字号)of text in students' textbooks should be no smaller than nine-point.Teachers should avoid(避免)using teaching equipment that is too bright, Beijing Daily reported. There are also requirements for desks and classroom lights. For example, these lights should give off as little blue light as possible.
   Blue light is bad for our eyes, because it can kill the photoreceptor cells(感光细胞)we need for our eyesight, according to Harvard Medical School. Many of the electronic devices we use every day, such as our phones and computer sereens, produce blue light.
1.Why was Sun Run in a big surprise?
A. Because her eyesight was always not good.
B. Because her friends had the same problem.
C. Because her eyes felt a little tired sometimes.
D. Because her eyesight dropped quickly.
2. What does the underlined phrase "give off" mean in Chinese?
A.释放  B．泄露  C.发射   D.长出
3. What are necessary for students'eyesight?
A. Bright lights.
B. Photoreceptor cells.
C. Electronic devices.
D. Teaching tools with blue light.
4. What do we learn from the requirements in the text?
A. The textbooks will be larger than before.
B. The government cares for students'health.
C. Students need over 2 hours' exercise a day.
D. The classroom lights won't give off blue light.
5. What is the last paragraph mainly about?
A. How to deal with blue light.
B.How to use blue light properly.
C. Where blue light is from and how it affects us.
D. Why computers can give off blue light.