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.

Today, many students are always stressed out. They are often too busy to think{#blank#}1{#/blank#} their diets and exercise. Healthy eating, along with regular(定期的) exercise {#blank#}2{#/blank#} (keep) you healthy. Do you think it is the only way to keep us in {#blank#}3{#/blank#}(healthy)?

As we know, it is important to give your body the energy it needs. Teenage girls {#blank#}4{#/blank#} (need) about 2,200 calories(卡路里) a day and boys need a bit more. {#blank#}5{#/blank#} (fiftieth) percent of your calories should come from rice, bread, {#blank#}6{#/blank#}(vegetable) and fruit. You also need to d{#blank#}7{#/blank#} a lot of water, six to eight glasses a day. Enough water will improve your skin and give you healthy hair.

Exercise can help to make you look good, feel good {#blank#}8{#/blank#} be healthy. Scientists suggest that teenagers should spend at{#blank#}9{#/blank#}(little) 30 minutes exercising every day.

Exercise can make you feel {#blank#}10{#/blank#} (relax)and energetic. It can even help you sleep better at night.

Let's eat healthily and take more exercise.

    We're sitting too much and it's dangerous. Most Americans spend more than seven hours sitting every day, and the more you sit, the weaker your body will be. Fortunately, there are simple changes you can make during the day—anywhere, even at the workplace—to improve your health.

    Park a few blocks away from the office each morning and walk to work.

    This allows you to start off your mornings actively and be ready to take on the work. If you take the bus, get off one stop earlier to take some light exercise before 8 a.m.

    Get up and move around the office once every 60~90 minutes.

    When you're busy with work, it's easy to forget the time. Set the alarm to remind you to get up and take a walk around the office. You can use this time to fill up your water bottle or go to the bathroom.

    Ask questions and discuss questions face to face.

    Go to your co-workers' office to discuss questions face to face, rather than send an email every time you have a question. This gives you a good excuse to move.

    Use your lunch break to move around outside.

    So many Americans today work during their lunch break. When possible, take advantage of this time to walk outside and enjoy the nice weather. Fresh air can make you keep a clear mind.

There is an English saying:" Laughter is the best medicine." Until {#blank#}1{#/blank#}, few people took the saying seriously. Now however, doctors have begun to look into laughter and the effects it has on the human body. They find that it {#blank#}2{#/blank#} people's blood pressure, the heart beating and breathing. It {#blank#}3{#/blank#} works the stomach and even the feet. So laughter exercises the body and improves people's health.

As a result of these discoveries, some doctors in the United States now hold laughter clinics; in which they help to improve their patients' condition {#blank#}4{#/blank#} encouraging them to laugh. They have found that even if their patients do not really feel like {#blank#}5{#/blank#}, making them smile is enough to produce beneficial effects similar to those caused by laughter.

Early to bed and early to rise makes a man healthy, wealthy (富有) and wise (聪明). This is an old English saying. It means that we should go to bed early at night and get up early in the morning. If we do, we shall be healthy. We shall also be rich and clever.

Is this true? Perhaps it is. The body must have enough sleep. Children of your age need ten hours' sleep every night. If you go to bed late, you can't have enough sleep. Then you can't think carefully and your homework will be wrong. You will not be wise and you may not become wealthy!

Some people go to bed late at night and get up late in the morning. This is not good for them. We should sleep at night when it is dark. The dark helps us sleep well. When the daylight comes, we should get up. This is the time for exercise. If the body is not used, it will become weak.

Exercise keeps it strong. Exercise helps the blood (血液) to move around inside the body. Blood takes nutrition (营养) to all parts of our bodies. The brains (大脑) in our heads also need blood. We think with our brains. If we keep our bodies healthy, and take exercise, we can think better!

Our bodies also need air to breathe (呼吸). Without air we will die. Get up early in the morning and we can have plenty of clean, fresh air. That will keep us healthy and happy.

①As missing children get older，they become quite different from the faces in their last﹣known photographs，which makes finding the really difficult. Now AI（人工智能）can make it easier to match any found children to those old photos. 

②Police can use software（软件）to age photos of missing people，but it seems to work best in adults

③Unlike adults ，the faces of children change greatly as time goes by，and matching photos of found children to old images（画像）（数据库）of missing children is difficult. "Even with a recent face image of a child，it is quite hard for a human to recognize（辨认），who the child is from a large data set of child face images，" says Debayan Deb at Michigan State University. 

④Now Deb and his teammates have created an algorithm（算法）to work out the problem. They created a face﹣recognition algorithm on data sets，which have images of nearly 1

⑤AI learned to match recent photographs of children with images taken 2. 5 years earlier. The correct matching rate can be 80 percent. With one year between the two photographs，it was 90 percent correct at recognizing faces. This dropped to 73 percent after three years. The new AI might help to improve accuracy （准确性）of this kind of software

⑥Deb's next goal（目标 ）is to make the age gap wider. His team also hopes to develop an app to fight against the sale of children.