Taking away a city's rubbish is a big job. Every day tracks come into a city to collect it. Most rubbish is made up of things we can't eat or use. If we kept these things we would soon have a mountain of rubbish.

    In some cities the rubbish is collected and taken outside of city to a dump. Often the city dump is placed where the ground is low or there is a big hole. The kitchen rubbish is broken into small pieces and sent into the sewage system. The sewage system takes away the used water from toilets, bathtubs and other places.

    To keep mice and flies away, some earth is used to cover the newly dumped rubbish. Later, grass may be planted on the rubbish-filled land. Finally, a house or a school may be built there, and then you'd never know that this had once been an old rubbish dump.

    In other cities the rubbish is burnt in special places. The fire burns everything but the metal. Sometimes the metal can be used again in factories where things are made of metal. The food parts of rubbish are put in special piles where they slowly change into something called humus, which looks like black earth. It is rich with the kinds of things that feed plants and help make them grow.

    In ancient Chinese stories, the moon is home to Chang'e and her pet rabbit Yutu. Now, Chang'e and Yutu are really there!

    On Dec. 2, 2013, the Chang'e-3 lunar probe（月球探测器）took off from Sichuan, China. On Dec. 14, 2013, it landed successfully on the moon. Several hours later, Yutu, China's first moon rover（月球车）, "walked" out of the probe and onto the moon.

    Yutu is a big robot that weighs 140 kg. It is about 1.5 meters long and 1.1 meters tall. It has six wheels and travels at 200 meters per hour.

    There are cameras on both Yutu and Chang'e-3. They can take pictures of each other. That's how Yutu got is first picture on the moon.

    Yutu and Chang'e-3 will explore（探索）the moon.

    Yutu can walk around and work for three months. It can look for natural resources（资源）on the moon. Chang'e-3 can work at the landing site for one year and it can watch the space from the moon.

    They both get energy from the sun. So they "get up" to work when the sun rises, and "go to sleep" at night.

    China is now the third country in the world to soft-land on the moon after the US and the former Soviet Union.

    Also, China is planning to send its Chang'e-5 lunar probe around 2017. The probe will fly back to the Earth and bring natural resources from the moon.

    When will China fly a human to the moon? There's no plan yet. But the door is now open.

    Life in space is much different from life on earth. How do astronauts live in space?

    Eating    In the past, astronauts could only eat small pieces of dried food. But now they are able to eat more everyday food like fruit, vegetables and ice-cream.

    Sleeping    All the people on the ISS（国际空间站）have their own rooms. They should be tied（系）to their beds, or they'll fly away! That seems like a hard way to sleep, but astronauts say sleeping is really not too bad.

    Exercising    This is more important in space than on earth. Astronauts exercise on bikes and other machines（机器）for about two hours every day. That way, they can still be healthy when they get back home.

    Having fun    Astronauts can read books, play cards, listen to music or send emails to their friends and families when they aren't working. Sometimes they just sit and look out of the window. It's also much fun!

    Hi, everyone. I'm Tina. I think our life in 2060 will be different from our life at the moment. There will be many robots in my house. Because robots will be cheap. And these robots will help my family do many kinds of work every day. Every morning the clock-robot will ask me to get up. Then the clothing-robot will dress me quickly. Next the kitchen-robot will make breakfast for me. When I get out of the house with my schoolbag, a car-robot will wait for me. After I show it my school ID card, the car will go. And then the car-robot will check my homework. When we get to school, the car-robot will say to me "See you tomorrow, Tina. Good luck."

    In the morning, I will have three lessons with my classmates. We'll study on the Internet. We'll use the e-book. The teachers are all robots. They are in different sizes and they can answer any question about any subject. In the afternoon, we'll go to the science lab to have two classes in a new plane. After class, we'll play football with robots. My classmates and robots can all be my friends. Don't you think the life with robots in the future will be fantastic?

    Have you noticed the waste bins(垃圾桶) in different colors on the street? Do you often put all the waste in the same bin? It's reported by Changchun Daily that people must do waste sorting(分类)in most places in Changchun at the end of 2019. Waste sorting is a wonderful way to make good use of energy and protect the environment. But do you know how to sort the waste?

    Usually, people should sort their waste into four groups: wet, recyclable, harmful and dry. Different kinds of waste should go into different bins. Wet waste means the things you don't want but pigs can eat, mostly coming from your kitchen. Things that can be used again, such as paper, metal and glass, are recyclable waste. Harmful waste might be dangerous or cause serious pollution, like medicine and batteries(电池). And any waste that's not wet, recyclable or harmful will go into the dry waste bin.

    Different countries are trying different methods to sort the waste. A university in England has invented a smart bin. When people drop their waste into the bin. It can tell what kind of waste it it and sort it correctly. The bin can also compress the waste to make it smaller in size and take up less space. In South Korea, people have to separate their food waste from other kinds of waste and pay for it. The more food waste they throw away, the more they pay. Japan has the strictest rules for waste sorting in the world. For example, plastic bottles and their caps should go into different bins.