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.

    Obesity (肥胖症) is becoming a problem in our busy society, almost one in three American adults is now considered to be obese. Children obesity is also at an all-time high.

    Obesity means being very overweight. If you are obese, you have too much body-fat. If you eat more food than your body can use, this will make you put on weight. Food that your body does not need will be stored (储存) as fat by your body.

    The following are the major factors (因素) that increase the risk of obesity.

    What you eat plays a major role in weight gain. Eating a lot of fattening food such as hamburgers, sweet drinks, ice creams and other sweet food can increase the risk of becoming obese.

    If you do not do enough exercise, you will put on weight as the food you eat is not being used to make energy for physical activities.

    The chances of your being obese are greater if your parents are obese.

    There are many psychological (心理的) factors that cause people to eat too much. People who are worried, unhappy or bored will often eat to make themselves feel better. This is known as comfort eating.

    Age is another factor, as you tend (趋于) to be less active when you get older. When you get older, you need to eat less, and if you do not eat less, you will put on weight.

    Obesity can cause many health problems such as heart problems, high blood pressure and many other serious medical conditions.

Do you like to have any online classes? It is becoming 1 to take classes at home during the early 2020. All you need is a computer or a cellphone. However, most students don't seem to like online classes. A 2 shows that only 33% of over 1,500 students from 10 cities would take such classes.

Many students said it was difficult to focus(集中) on 3 while taking online classes. Lian Ruohan, 15, at the Affiliated High school of Peking University, said, "There are no real classmates sitting near me; no real teachers watching me. I can easily surf the Internet or do 4 things if I want to. It's harder to be always focused."

In order to avoid that, Lian will prepare a lot before classes to make sure she will learn 5 in class. She also pushes herself to communicate(沟通) with teachers about difficulties. She often 6 or answers questions while taking online classes.

Wen Jiayi, 14, at the Yucai Middle School, thinks online interaction(互动) isn't 7. "I have few chances to communicate with the online teachers, and they don't really get to know me. When I don't hand in homework, all I get is only a short telephone 8 instead of real care," she said.

However, Lian thinks online classes still have many 9. "It saves time and money compared to(和……相比较) taking official classes. Also, if I can't 10 some part of a lesson, I can watch it again to make it clear."

A Chemical reactions(化学反应)make for some great experiments.You can make use of the CO₂ (carbon dioxide) given of by a baking soda and lemon Juice reaction to blow up your balloon! 

What you'll need:

★Balloon 

★About 40 ml of water (a cup is about 250 ml so you don't need much) 

★Soft drink bottle ★Juice from a lemon 

★1 teaspoon of baking soda Instructions: 

★Before you begin, make sure that you pull the balloon long to make it as easy as possible to blow up. 

★Put the 40 ml of water into the soft drink bottle. 

★Add the baking soda and mix it with water. 

★Put the lemon juice in and quickly put the balloon over the mouth of the bottle. 

What's happening?

If all goes well, then your balloon should inflate(膨胀)! Adding the lemon juice to the baking soda creates a chemical reaction and produces CO₂. The gas rises up and escapes through the soft drink bottle. It doesn't, however, escape the balloon, pushing it outwards and blowing it up. 

注意：1、观点明确，语句连贯、通顺；2、词数80字左右，短文的开头已给出不计入总数。

3、常用句型：（1）The students of our class have different ideas about... （2）Some parents think...（3）These years, some students are interested in... I like... but I hate...（4）Firstly, ... Secondly, ... Thirdly,... （5）In my opinion..

Many people like to travel by plane(飞机), but I don't like it because the airport is {#blank#}1{#/blank#}(usual)far from the center of the city. You have to get there early and wait for hours for {#blank#}2{#/blank#}plane to take in and it is often late. You can't open the {#blank#}3{#/blank#}(window). You can't choose(选择) the food. 

I like traveling {#blank#}4{#/blank#}train. I think trains are safe(安全的). Railway stations are usually in cities. When you {#blank#}5{#/blank#}(be)late for a train, you can catch another one. You can. {#blank#}6{#/blank#}(walk) around in the train and open the windows. You can see many interesting things on your way. I know it {#blank#}7{#/blank#}(take)a little more time. 

I also like cars. You can start{#blank#}8{#/blank#}(you)journey(旅程) when you want to, and you don't need to get to a railway station {#blank#}9{#/blank#}a bus stop. Also you can carry many {#blank#}10{#/blank#}(thing)with you in a car. But sometimes there are too many cars on the road.