Most of us spend a third of our lives sleeping. Scientists have been studying the brain to learn what happens while we sleep. Scientists tell us that there are four stages(阶段)of sleep. During each stage our brain behaves differently, and so does our body. Each stage is marked by changes in the pattern of brain waves, which can be recorded by machines.

    In the first stage, we drift off to sleep. Our muscles(肌肉)begin to relax. Our heartbeat and breathing slow down. Body temperature and blood pressure(压力)begin to drop. Stage-two sleep is a time of small, fast brain waves. Our eyes move quickly from side to side as if watching a movie. This is known as rapid eye movement, or REM sleep. During REM sleep, dreaming takes place. In stage three the brain wave becomes slower again.

    Within about 45 minutes after falling sleep, we progress into the fourth stage – deep sleep. As this happens, our brain sends out slower but larger brain waves. This is the most restful kind of sleep, but it is also the time when sleepers are most likely to change positions or sleepwalk. After deep sleep we return to stage two. As the hours pass, we repeat the sleep cycle four or five times. Then we wake up.

    Although Tokyo is one of the most expensive cities in the world, you will be surprised that there are still some free activities in Tokyo.

Free temples

    There are many temples in Tokyo. The most famous one is Meiji Jingu. This is the most important temple in Tokyo. If you visit it, you can know more about Japanese history. Of course, it's free.

Free museums

    If you go to Kanto Earthquake Museum, you can see the exhibitions and the memorial for the people who died in the 1923 earthquake disaster.

Free parks

    There are two famous parks in Japan. They are Yoyogi Park and Ueno Park. Yoyogi Park is one of the largest parks in Tokyo. It is now a great place to see street performances. Ueno Park is popular with many Japanese people and foreign visitors.

Free snacks

    Japanese food is delicious and healthy. You can try different kinds of snacks, before spending money on them. You don't need to pay for them when you try them.

Waste sorting (垃圾分类) has come. It's so important to us humans. We do waste sorting before throwing rubbish away. We are happy to see some fine examples. However, it is not easy for everyone to do this. Some people may spend so much time deciding the kind of the rubbish. Luckily, the twin sisters front Beijing developed an app (应用程序) to help solve the problem.

The app is easy. When users need to throw away their rubbish, they open the app first. In the app, they can find the names of different rubbish. Then, they choose a kind of rubbish in the app, and the right rubbish bin (箱) will open. The app is also helpful. It makes use of speech recognition (语音识别) technology. Then users can just speak out the name of the rubbish, and the rubbish bin will open. 

In fact, waste sorting isn't difficult, but we need some time to get used to it. Of course, technology can help us to do it better.

The 19^th Asian Games（亚运会）is held in Hangzhou, China this autumn. Many sportsmen come to the Games. They are from different{#blank#}1{#/blank#}in Asia. There{#blank#}2{#/blank#}three mascots（吉祥物）of the Hangzhou Asian Games. They are Chenchen, Congcong{#blank#}3{#/blank#}Lianlian. They are very cute and friendly. Everyone{#blank#}4{#/blank#}them. The sports gym looks{#blank#}5{#/blank#}a flower. It's beautiful, and it's{#blank#}6{#/blank#}big.

There are lots of games. I can watch{#blank#}7{#/blank#}on TV. My{#blank#}8{#/blank#}game is the men's skateboarding. The champion（冠军）is Chen Ye. Chen is from China. He is{#blank#}9{#/blank#}. He is 15 years old, and he is a{#blank#}10{#/blank#}in Huizhou. I am a student in Huizhou, too. I am so proud（骄傲）of him.

Twenty percent of all the water that goes into oceans around the world comes from one river — the Amazon.

The Amazon River{#blank#}1{#/blank#}from the Andes Mountains in Peru.It travels about 6，400 kilometres to the Atlantic Ocean.It is the largest river in the world.It is{#blank#}2{#/blank#}the second longest.Most of the Amazon's water comes from rain.During the rainy season, parts of the{#blank#}3{#/blank#}are 190 kilometres wide.

The Amazon River goes through the world's largest{#blank#}4{#/blank#}forest.The Amazon rain forest is home to the largest{#blank#}5{#/blank#}of plants and animal species(物种) on Earth.There are 2.5 million kinds of insects,{#blank#}6{#/blank#} the world's largest ant.At least 3，000 kinds of fish and one­fifth of all the bird species in the world{#blank#}7{#/blank#}there.Some of the Amazon's animals are{#blank#}8{#/blank#}， such as the anaconda(水蟒), so people should be careful.There are also gentle animals, like the sloth(树懒){#blank#}9{#/blank#} the pink dolphin.

The Amazon is very important to Earth.There are still many kinds of animals and plants there that we don't know about.If we lose the Amazon, we will{#blank#}10{#/blank#}a big part of life on Earth.