We've talked about snails (蜗牛) and their slow move . But much of the time snails don't move at all. They're in their shells (壳)—sleeping .

    Hot sun will dry out a snail's body. So at the least sign of hot sun, a snail draws its body into its shell and closes the opening with a thin cover .Then it goes to sleep. A snail will die in a heavy rain. So whenever it rains, it goes inside its shell house and goes to sleep. A snail can sleep for as long as it needs to. It can take a short sleep. Or it can sleep for days at a time .And it spends all the winter months in its shell, asleep.

    In spring the snail wakes up .Its body, about three inches long, comes out of from the shell. When hungry, the snail looks for food. It can't see very well. Its eyes ,at the ends of the top feelers (触角)are very weak . But its sense of smell is very strong. It helps the snail to the new greens. Then the snail's little mouth goes to work.

    A snail's mouth is no longer than the point of a pin(针) . Yet it has 256,000 teeth! The teeth are so small that you can't see them. But they do their work. If you put a snail in a hard paper box, it will eat its way out. And if a snail wears out its teeth, it will grow new ones.

    Mostly, a snail looks for food at night .But on cloudy days it eats in the daytime. It eats all day long. A snail can go on eating for hours and never feel full.

    How green are you? Do you know how to be green?

    We all need a healthy environment, but we produce waste every day and it does harm to our environment. Though we are young, we can still do something to help. In fact, even the simplest everyday activities can make a real difference to the environment. Here are some ideas for you.

    Reduce

    Reduce means "use less". Don't waste things. This saves money and reduces pollution and waste going into the environment. Before we buy something new, think whether it is really necessary—or maybe the old one will be just as good! When we buy things, choose local products if possible, and try not to buy too many things from abroad.

    Reuse

    Reuse means "use again". Use things for as long as possible. When we buy things, make sure that they last a long time. We should look after them so that they will last, and we should repair them if we can instead of throwing them away and buying new ones. Don't use a paper cup or a paper bag. It's better to use a china (瓷器) cup and a lunch box because you can use them again.

    Recycle

    Recycle means "change things into something else". Though it takes energy to change something into something else, it's better than throwing things away or burning them. Find out what can be recycled in your neighbourhood and take part in recycling programmes. We should also buy products made from recycled materials, such as recycled paper, to help save trees.

    So please remember these three words: reduce, reuse and recycle.

The opening ceremony of the Hangzhou Asian Games marked the richest and most skillful use of AR (增强现实技术) in history. 

"Technologies such as AR have allowed us to express more, " said Sha Xiaolan, director of the opening ceremony. "We've fully put AR into the opening ceremony. It offers people special experience to feel Chinese culture in Hangzhou. "

At 8 p. m. on Saturday at the Hangzhou Olympic Sports Centre Stadium, the opening ceremony started with an amazing performance. It showed the culture, history and natural beauty of Hangzhou and Zhejiang. 

The technologies were fully used into each of the programs from beginning to end. It started with Kongming Lanterns and ended up with digital (数字的) fireworks and a digital torchbearer（火

炬手）. All of these meant Hangzhou's promise to be an environmentally friendly Asian Games.

"You saw a little AR during the closing ceremony at the Beijing 2022 Olympic Winter Games. But it was fully a part of the performance and brought things like water to life at this ceremony. " Sha Xiaolan said. "Because of it, the opening ceremony was beyond expectations（超出预期）. "

Do you know Machu Picchu in Peru? Maybe you never hear about it and think there is nothing great with it. But it is famous all over the world, just like the Great Wall in our country.

Machu Picchu is over 600 years old, but people found it very late, in 

1911. That's why people also call it"The Lost City of the Incas". Machu Piechu lies on the highland of a mountain, at over 2,400 metres above sea level. It is about 5 km² and has about 200 different old but great buildings. There are three areas(地区) in Machu Picchu and every one of them has different uses. The slopes(斜坡)of the mountain work as the farming areas. The lower (更低的) areas are the buildings for people to live in. The top of the mountain is for religious activities(宗教活动). From there, you can enjoy all of Machu Picchu.

▲Why did people build the city on the mountain? How did they build these fantastic buildings? Who lived there before? It may take a long time to find them out.

It seems that on every street corner in the world, there is a fast-food restaurant.People everywhere are busy. {#blank#}1{#/blank#} Around the world,$240 billion a year is spent on fast food. Yet, even though fast food has becomequite popular，there are many myths（荒诞的说法）about it，

{#blank#}2{#/blank#}This is not true. More than 2.000 years ago,the people of Rome lined up in the street to buy quick meals at small stands（摊位）.One type of their most popular fast food looked a lot like a modern hamburger. All through history, people have always eaten fast food.

The second myth is that all fast food is American. While many modern fast-food restaurants are American, some very traditional Chinese food is nearly fast food. {#blank#}3{#/blank#} in fact,one of the most popular fast food chains (连锁店）In the US is a Chinese food chain, Panda Express. It has more than 1,600 restaurants in America.

Finally,many people think that fast food is always bad for them. This is true for a lot of fast food.However ,nearly every fast-food restaurant has some healthy food on its menu,and some fast-food restaurants also make healthy food. {#blank#}4{#/blank#} We can choose to eat healthy food. even at fast-food restaurants.