6 . April 22 is Earth Day. Everyone on the earth should care about and protect the earth!

The earth has warmed by about 1°F (华氏度) over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. But many scientists say that people are doing many things which make the earth warmer.

First, the greenhouse effect (温室效应) is a very important reason for the change of the earth. People give out too much energy into the air every year. It makes the earth warmer. Climate (气候) change is another important reason. Sometimes it becomes too hot and sometimes too cold. Sometimes there is too much rain and sometimes too little. The change of the climate makes the earth warmer. In turn, the warmth of the earth changes the climate, too.

People can affect the earth’s air, land and water. As for us, we can do many things to protect the earth. For example, we can use fridges less. We can tell more people about protecting the earth.

7 . Thanks to better health care, most people are living healthier and longer lives. Someone who is born today can expect to live about thirty-five years longer than someone who was born in the nineteenth century. It is even thought that in the future more and more people will celebrate their hundredth birthdays. Here are some rules for a healthy life.

Get off the sofa!

Sure, it is comfortable to sit on the sofa and watch TV. But doctors say you should get off the sofa. To keep fit, you have to walk at least 10,000 steps every day. In the past, people’s jobs required more physical effort. They often had to walk for miles every day. When farmers were working in the fields, they were keeping fit at the same time. Think about it: Do you get the same amount of exercise today as they did in the past?

Eat healthy food!

It is important to eat food that is fresh and natural, for example, fruit and vegetables. Fast food is not healthy. You should only have it once in a while. Eating too much of the wrong food will harm your health.

Rest while you can!

When we were babies, we slept for much of the night. Teenagers do not need as much sleep as babies, but it is important for you to get about eight hours’ sleep a night. At weekends, you have got more time, so use it not just for your friends, but for rest too.

Do not worry. Be happy!

Many people believe that happiness is important for our general health. Sometimes it is not easy to be a teenager because of the difficulties of school, exams or friendships. If you are worried about something, talk to your parents or your teacher.

8 . Artificial intelligence(人工智能), or AI in short, is the science of giving computers and machines ability to think and work like humans. AI scientists and engineers have made a lot of cool technologies.

AI is rapidly catching up with the human ability to read faces. As a result, facial recognition(识别) is used a lot in the world. Chinese police use this technology to identify criminals(罪犯). Once they caught a criminal when he attended a concert. It also checks the ID of ride-hailing(网约车) drivers and lets people pay for things with a smile.

AI is also used in self-driving cars, which are believed to be the future of driving. Most drivers may wave or nod at passers-by to let them cross the street, but self-driving cars don't have this ability. Carmakers are testing a light signal system to help them "speak" to humans. The system can show what self-driving cars will do. For example, if a driverless car is yielding(让路), it will flash two white lights side to side. A rapidly flashing light tells passers-by that the car is about to speed up.

Service Robots also show you how powerful AI is. Imagine this—you come back home from school and your robot housekeeper is waiting for you at the door. After dinner, he teaches you to play the piano, just like a real music teacher. Such thoughts will soon happen in the real world. In the future, more and more service robots will become good home helpers.

AI is so powerful that it can help human beings and even replace us in many jobs.

Qomolangma is the world's highest mountain. You may have learned from your textbooks that its height is 8,844.43 meters. But not all sides are in agreement on this. Different researchers have given different results. In addition, the height of the mountain can change over time.

That's why a Chinese survey team with over 30 members set out to reach the peak of Qomolangma to re­measure its height on May 6, 2020. They were equipped (配备) with the latest technology.

It is not an easy task. The average air temperature on the mountain is ­-29℃, and powerful winds blow all the time. In such bad conditions, surveying drones (无人机) cannot work at the peak of the mountain. That's why it's still necessary to send human experts to the peak to get exact results.

But does a difference of a few meters really matter when it comes to a high mountain?

In fact, measuring the height of Qomolangma is about more than just getting one exact number. Mount Qomolangma is at the point where the Eurasian plate (欧亚板块) meets the Indian plate. It formed 38 million years ago as the two plates hit each other. Changes in the peak's height can show whether the two plates are heading toward or away from each other. This can help us understand the movement of the earth's crust (地壳).

The survey team will also get first­hand information about environmental conditions at the top of the mountain. This will help us understand how climate change has affected the Qinghai­Tibet Plateau (高原).

10 . Shameem was born in a small village in Pakistan. In her village, it was a tradition to keep girls inside their homes. They were not allowed to get an education.

Fortunately, Shameem’s uncle, a university teacher, wanted to give her a chance to see the world. He offered Shameem a chance to attend school. So she became the only girl student in her class.

However, Shameem struggled to complete her schooling. To get permission for college, she went to a three-day hunger strike(抗议). After graduating from college, Shameem got a position in a non-profit organization(非营利性组织) working to help women in rural( 农村的) areas.

There, she saw a Pakistan that she didn’t know. Until then, she thought she had a difficult life. But there, she saw what women in other parts of Pakistan were experiencing. Some women had 11 children, but nothing to feed them. They would walk three hours every day to get water.

Shameem found that the position was more than just a job for her. She discovered her power. By setting an example, her experience could encourage more people to understand the importance of education and send their daughters to school.

Now, Shameem teaches in a rural school in her hometown. “The first day I walked into the school,” she said, “I saw all these little Shameems staring at me with dreams in their eyes, the same dream of freedom which I had in my childhood.”

Today, there is not a single girl in her village who doesn’t go to school.