Tornadoes(龙卷风) are one of the worst weather events on earth. Each year, tornadoes kill many people. The storms often carry homes, cars and trees from one place to another. And they can also destroy anything when they pass by.

      A tornado comes from a thunderstorm(雷雨) in the sky down to the ground. It is big at the top and small at the bottom.

      A tornado appears when winds in different directions meet in the cloud and begin to turn in circles. People can see tornadoes almost everywhere in the world. But most happen from late winter to middle summer. There is a second high season in November. During spring, warm air moves north and mixes with the cold air left from winter. In November, the opposite happens. Cold air moves south and mixes with the warm air left from summer.

      Tornadoes always come suddenly. Weather scientists have done something to predict(预测) tornadoes. But the storms often move too fast for people to protect themselves. Last year, tornadoes killed more than one hundred people in United States.

      Scientists say the best place to be in is a small room, without windows, in the middle the lowest part of a building when tornadoes come.

    What will life in the future be like? Will it be much better than it is now? And what will we be able to do in 10, 20 or 30 years' time?

    Genetic engineering (基因工程)may help us make the perfect human. Babies may grow up to play basketball like Yao Ming or look like Cecilia Cheung. Also, we may be able to bring the dead back to life. Maybe people will be able to meet and talk with their dead family members.

    Over the next 20 to 50 years, it will become harder to tell the difference between humans and machines. Perhaps we will be able to make copies of ourselves, so we will appear to be alive long after we are dead. People may be able to find ways of putting the life of a person into a new body.

    Nanobots(纳米机器人)will be important. We will use them when we are sick. For example, when we have a stomachache, we will swallow (吞下) a nanobot and it will travel through our stomach, taking a video of what's happening there. The video will help the doctor cure us.

    In the future, computers may have their feelings. They may be able to think better than us. We may be more and more interested in computers and the internet, spending all our time in front of computers. Perhaps we will forget our real needs. Perhaps we will become super couch potatoes weighing 250 kg!

Today, I want to tell you about a new app called Lost &. Found at school. You just need to search for the names of the things on the app. And then you can find them. Now look at these things on the app. Some students lost them this week. 

China's in﹣orbit Shenzhou﹣16 crew （全体人员），including Jing Haipeng，Zhu Yangzhu and Gui Haichao（网络直播） the first science class from the Mengtian lab module of the China Space Station for the first time on Thursday. 

It is the fourth lecture of the "Tiangong Class" series，China's space science education program，aiming at encouraging young people to achieve their space dreams. 

During the lecture，the crew showed their living and working environment in the Mengtian lab module （舱）. Connected with the Tianhe core module and Wentian lab module，formed a basic T﹣shape structure of the space station. 

The crew showed several interesting experiments in the microgravity （微重力） environment. For example，they showed how a candle flame （火焰），they explained the law of conservation of momentum （动量守恒） by showing the collision （碰撞）

The crew answered questions from the students in the end. When asked whether space rubbish can be seen from the space station and how the space station protects itself，Jing said that they haven't found any space rubbish so far. He said that space rubbish is harmful to the station，and said that the scientists on the ground will keep an eye on its move. "Once there is a threat （威胁），action would be taken，" he said. The space station is also protected by some special equipment. "Even if we meet space rubbish，" he added. 

The Shenzhou﹣16 crew set off to space on May 30，2023 and returned to the Dongfeng landing site in November of the same year. 

Jim got up and got dressed. Then, he looked at his toothbrush and he said, "In 2024, I will brush my teeth after every meal." Haha, the toothbrush fell over! Jim went downstairs and he looked at his mother and he said, "In 2024, I will always be nice to you." and his mother smiled.

When Jim arrived at school, he didn't finish his homework and had no homework to hand in. He said to his teacher, Mr. Smith, "Sir, in 2024, I will always do my homework." Mr. Smith tutted (发出啧啧声) at Jim.

At lunchtime, Jim went to the canteen and he ate a burger and fries. He said to his friend, "In 2024, I will stop eating fast food and I will eat healthy food like chicken, fish and salad." Jim's friend just smiled.

When Jim arrived home after school, he ate his dinner and then he turned on his computer and he started playing computer games. He played for three hours and he said to himself, "In 2024, I will not play computer games all the time. I will play for only one hour a day." He looked in the mirror and he smiled to himself. You see, Jim made these resolutions last year, but he didn't keep any of them!

But this time, Jim really took these promises seriously! He thinks he can do it. Let's hope so!

There are more than 400,000 kinds of plants on Earth. Some plants are as big as tall buildings, others are as small as rice. Plants are an important part in nature because they give out oxygen. All animals need it for breathing.

What is a plant? Most people can find the differences between an animal and a plant. That is because animals can move around, but plants can't. What makes a plant? Like animals, plants are living things with lots of cells (细胞). Unlike animals, plants make their own food with water, CO₂ and sunlight. Most plants have roots, stems, and leaves, and most plants reproduce by growing flowers and making seeds. 

How does a plant grow? For most animals, genes (基因) control (控制) their growth. That means when they are small, it's easy to know what they will look like after they grow up. Plants are different. Genes controlled their growth too, but their final shapes may be different because of the place they live. For example, a tree can be big and round if it grows up in an open space (空间), but taller and thinner if it grows with many other trees around it. Plants can't move from one place to another, so it is important for them to fit (适应) in the place they live.