There are many kinds of trees. All trees have roots. The roots hold trees in the ground. The roots soak up ( 吸收 ) water and food. Then trees get water and food from the roots. You can't see inside a tree. But you can study how water moves through trees.

    First, get a stalk ( 茎 ) of celery ( 芹菜 ) and cut off its end. Put red colour in a cup of water. Then put the stalk of the celery into the red water. Then we can see the red water moving up in the celery easily.

    After half an hour, take the celery out. Cut it in half. Your celery should be red. This is because the water moved up the stalk. Water moves through trees in the same way as it moved through the celery.

    Beautysleep is a real thing, researches have shown that people who have enough sleeplook more attractive (有魅力的) to others.

    A few badnights are enough to make a person look especially "more ugly", theirsleep experiments show.

    Theresearchers asked 25 university students to join in their sleep experiment.They were asked to get a good night's sleep for two nights.

    A weeklater, they were asked to sleep for only four hour every night for two nightsin a row. The researchers took make—up free (素颜) photos of the volunteers afterboth the good and the bad sleep.

    Next, theyasked 122 strangers to have a look at the photos and judge (评价) them on attractiveness, health,and sleepiness, as well as asking them: "How much would you like to makefriends with this person in the picture?"

    Thestrangers were good at judging whether the person they were looking at wastired, and if he was sleepy, his attractiveness score would be low.

    Thestrangers also said they wouldn't want tosocialize with the tiredstudents. The researchers say this is natural for people. An unhealthy-lookingface makes people run away. In other words, people don't want to hang aroundwith people who might be ill.

    Dr Brewer,an expert at the University of Liverpool said: "Judgment of attractivenessis often unconscious (无意识的), but we all do it, and we are able to judge on even somethingsmall like whether someone looks tired or unhealthy. This study is a goodreminder of how important sleep is to us."

The ISS is as tall as a nine﹣story building and weighs 186，900 kilograms. It's about the size of two football fields and flies about 400 kilometers above our heads at 28，970 kilometers per hour. It goes around Earth once every 90 minutes. 

If you watch the sky for about an hour after the sun goes down，you may see some "moving stars". But they are not really stars. They are man﹣made satellites. And the biggest of all is the International Space Station （ISS）. From May to July is the best season to watch the ISS flying over the earth. And people can see it with their eyes during the time. 

The scientists want to live on the ISS. They think that the best way to learn more about space is to live there. 

When the space station is finished，it will be like a city in space. People will stay and study there with many of the thing they have at home. Laboratories，living rooms and power stations are being built. The ISS is the most ambitious（雄心勃勃的）

Scientists hope that the ISS will be a stepping stone（跳板） for future space exploration. "The ISS will be more useful some day. The ISS will help us understand the human body better，explore space and study the earth. It can help us make life on the earth better. " said Kathryn Clark

Sixteen countries are part of the space program：the US，Russia，Canada，Brazil，and 11 European countries. 

China isn't an ISS country，but it has helped with some of the experiments. In 2003，China sent some rice up to the ISS to find out what space would do to it. 

After it's finished，more than 90 percent of the world's population is able to see the Space Station. So keep looking up，and maybe you'll see it getting bigger. 

难度系数：★★

We live in the age of the computer. Scientists, teachers, writers and even students use{#blank#}1{#/blank#} to do all kinds of work. {#blank#}2{#/blank#}, more than thirty years ago, computers couldn't do much work. They were big and expensive. Only a few people were {#blank#}3{#/blank#} in them and knew how to use them. Today computers are smaller and {#blank#}4{#/blank#}. They can do a lot of work for people.

Computers play {#blank#}5{#/blank#} important role in our everyday life. They can work faster than people. Besides, they {#blank#}6{#/blank#} fewer mistakes. Computers can help people {#blank#}7{#/blank#} different work. {#blank#}8{#/blank#} use them to write articles. Teachers use {#blank#}9{#/blank#} to give lessons. Students use them to study Nowadays computers are necessary in our daily life. They make our life easier and more interesting. What do you think our lives will {#blank#}10{#/blank#} like without computers?

The opening ceremony(开幕式) of the 19th Asian Games in Hangzhou was held on September 23ⁿd,

2023. People could see the electronic fireworks (烟花) in the night sky above the Hangzhou Olympic Sports Center Stadium. It showed us beautiful pictures, the latest technologies and environmental thoughts.

" The electronic fireworks paid attention to environmental protection," said Sha Xiaolan, the director of the opening ceremony." As long as fireworks are set off, there will be smoke in the air. It will cause pollution. Compared with normal fireworks which we usually set off, electronic fireworks never produce smoke and noise."

Why did they use this kind of fireworks? Because they were ' green', and Sha Xiaolan hoped to show environmental protection to the world. It did not mean there would be less excitement of the opening ceremony. According to the digital technology, 3D pictures, AR technology and more, the electronic fireworks have left a deep thinking on the people." People have rich feelings while they are watching the fireworks. Today is the first time I have seen electronic fireworks, and they are very eye- catching." He told China News reporters.

" High technologies helped produce environmental- friendly fireworks," Sha said." The research team designed fireworks with 3D technology. Then they did many experiments so that the fireworks had the best show without pollution."