Haiyan is 7 years old. Her parents gave her an iPad as a gift for her birthday. A month later，her eyesight（视力）dropped to 300 degrees. This is serious for such a young child.

    Many children in China are facing the same problem: iPad using is bringing problems to their eyesight. The problem is so common that newspapers even call the iPad the "No. 1 killer of children's eyesight!"

    "There are about 30 shortsighted children coming every day, "said Hu Dali, an eye doctor at Guiyang Aier Eye Hospital. "Half of those children have poor eyesight because they have played with phones and iPads for too long. "

    Doctors and scientists say children's vision（视觉）is not yet fully developed and their eyes get tired more easily. The screen of an iPad uses very bright（明亮的）LED backlight. If children look at an iPad screen for a long time, their eyes do not have time to rest. This will make their eyesight worse over time.

    Doctors advise that users should hold their iPads between 40-60 centimeters（厘米）away from them. The brightness of the screen should be comfortable for children. Parents should also stop their children from using an iPad for more than one hour every day.

    Li Qiang and Li Gang are brothers. But their living habits(习惯) are different. Now let's go to Li Qiang's room. Li Qiang cleans his bedroom every day and puts his things away. Look! There is a computer on the desk. There are two footballs under the bed. A guitar and a kite are on the wall. Some books are on the shelf. So he must be a careful boy. Now let's go to Li Gang's room. The room is not clean. There are some books on the floor. Can we see his clothes on the desk? Oh, yes. We can also see a football and a knife on the desk. Li Gang never does any cleaning. So his room is  in a mess(混乱).

    What do you think of Li Qiang and Li Gang? I think Li Qiang is a good boy. Li Gang must learn from his brother.

   Jack and Eason were walking through the forest. They knew that it was dangerous to do this because many wild animals live in the forest. As friends, they agreed that they would stay together and help each other if there was any danger.

    All of a sudden, they saw a large bear running toward them. Jack climbed a nearby tree. He didn't think about his friend at all.

    Unluckily, Eason did not know how to climb. He could only lie down on the ground. He held his breath and pretended(假装) to be dead.

    The bear came close to Eason. He smelled the man for a moment and left. You see, bears do not eat dead animals or people.

    After the bear walked away, Jack climbed down and went to Eason on the ground.

    "Are you okay? Did the bear hurt you? If only you could climb a tree," he said, not knowing that he didn't' follow their agreement(约定).

    Eason then answered, "Do you know what the bear told me? He told me do not believe afalse friend!"

It has been nearly 5 years since Chang'e-4, a Chinese spacecraft, made the first soft landing on the far side of the moon at 10:26 am on 3rd January 2019. It is the first time that a spacecraft has made it. The far side is the part of the moon that always faces away from the earth.

After it landed on the ground, the spacecraft took the first photo of the"dark side"of the moon, and sent it back to the earth through the Queqiao relay satellite(中继卫星).The scientists launched the satellite into space in May, 2018.

"What we know about the far side of the moon is from orbiters (轨道飞行器), from Russia, the US, European countries, China and India,"Andrew Coates, a professor of Physics at University College London, told a reporter. China sent Chang'e-4 into space from the Xichang Satellite Launch Centre in December,2018. Sending a spacecraft to the far side of the moon isn't easy, because the far side is covered in craters(火山口). Some of its mountains are higher than Qomolangma, the highest mountain on the earth.

What's more, we can't see the far side because it takes the moon about 28 days to move around the earth with the same side always facing our planet. Direct communication with the earth is impossible on the far side of the moon, so communications must go through a communication satellite. That was why scientists launched the Queqiao relay satellite.

Rock climbing（攀岩） did not become a sport until late in the 1900s. But now it has become a popular outdoor activity. While rock climbing may still be necessary for mountain climbing，most people just climb low mountains for fun. 

If you have ever done rock climbing，you will know that it is not a very easy sport. Indoor and outdoor rock climbing both need practice. What most people don't know is that rock climbing is one of the sports that depend on your body and mind（意志）. 

To climb successfully，one must use wonderful skills. One of the important rules is to always have three parts of your body on the rock face. Another important rule is that your arms only hold you close to the rock face while your legs are pushing you up，the closer you are to the rock face，the easier it is to climb. 

Rock climbing is a wonderful sport. Once you start to learn how to climb，you'll find more fun. People who like games such as chess playing or problem—solving may love rock climbing，because they are nearly the same in the way of thinking. For anyone who wants to get into beautiful shape，rock climbing is a fun and good way. Anyone who enjoys a difficult game and loves the outdoors should think of taking rock climbing as a new hobby. 

I was once a fat girl. I weighed 336 pounds and looked as big as my fridge. I was never 1 it. But one day I had a medical examination（体检）. The doctor told me that I was having heart trouble. It 2 me up. I began to feel nervous. Then I decided to do something!

In a year and five months, I3 104 pounds. What a great thing I did ! I didn't have any expensive food, medical treatment（治疗）or camp-style（训练营式的）exercise. What was the secret to my success?

First I looked through the Internet for do-it-yourself 4 that people could follow on losing weight. Of course I saw countless(无数的) ads which tried to get me to buy their products. But I bought nothing. The only thing I did was to change my bad 5 . The following are what I have done. You can try these. Stop drinking something with too much sugar in it. Refuse(拒绝)sweet cakes. Eat green vegetables. Use only vegetable oil. Never eat after 6:30 pm. Also, do light exercise for 15 to 20 minutes five days a week. 

Then I kept doing what I should do. People sometimes say, "You don't need to tell me 6 to do. I know it already!" But the fact is that knowing what to do and doing what you know are totally7 . The important thing is to know what to do and then just keep doing it. 。