Everyone has a body. Every part of the body is useful（有用的）. We can see with our eyes. We can eat with our mouth. We can hear with our ears. We can smell with our nose...

Is hair useful? It can keep our heads warm in cold days like a hat. The nose can clean and warm the air before the air goes into the body. When we eat meat or rice, we can use our teeth. If a body is two months old. It has two teeth. If a girl is four years old, she has twenty teeth. Her father or mother have 28-30 teeth. We must look after our bodies to keep us healthy（健康的）.

After fighting for three years due to the COVID-19 epidemic, thousands of runners finally could pour out from the starting line of marathons (马拉松), with crowds of people cheering along the way. According to the Chinese Athletics Association, a total of 133 marathons across the country have been planned for the first six months of the year. On March 26, more than 300, 000 runners took part in 26 marathon events nationwide, including many teenagers. 15-year-old boy Xu Qian and 16-year-old girl Li Yanzhuo were two of them. What a great inspiration the marathon is!

Unlike the 800-meter run at school which is more about speed, a marathon tests a runner’s endurance (耐力). In marathons, the only opponent you have to beat is yourself!

When things were hard, people from across the world cheered me on. Even if it was just the words ‘keep it up’, it meant a lot to me and I was inspired to keep going to the end.

History of the marathon

The first marathon of the modern Olympic Games took place in 1896. People do this to remember a soldier (士兵) in ancient Greece. Many years ago, there was a war between Greece and another country. Greece finally won. A soldier wanted to tell the king and everyone the good news, so he ran all the way to the palace. It was about 40 km away! He arrived and said, “We won!” But then he died because he was so tired.

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In the Olympic marathon, runners have to run 42.195 km. That’s about 105 laps (圈) of your school’s 400-meter track (跑道). Along the way, there are many drink stations. Runners can drink some water and keep running. Many countries and cities also hold marathons. Some are different from the Olympic marathon. For example, a half marathon is about 21 km long and a quarter marathon is 10.5 km. There are even mini-marathons for kids. They are only about 1 to 2 km long.

With more and more Chinese knowing and joining in marathons, our country is also becoming healthier and stronger!

Flying is a fast way to travel. But it is a big headache for some people. They can’t help worrying about things like “Is it dangerous if we don’t change our mobile phones to airplane mode (飞行模式)?” Here are some interesting facts about flying.

Why are plane windows round?

It’s for safety. As the airplane flies higher and higher, the atmospheric pressure (气压) outside gets lower and lower. During the flight, the pressure inside the plane becomes greater than the pressure outside. When this happens, square windows can break. That’s because having different pressures inside and outside puts stress on the corners of square windows. But rounded corners can spread the pressure more evenly (均匀地) across the window’s surface, making it less likely to break.

What happens when a phone isn’t in airplane mode?

Some passengers believe mobile phones and tablets(平板电脑) need to be turned off because they can bring the plane down. However, this is not true. If you don’t change your phone to airplane mode, pilots and air traffic controllers may hear unpleasant sounds in their headphones. This makes it harder for them to communicate. So it’s still best to put your devices (设备) in airplane mode.