He hurried to go to work, .

    MinecraftEDU, a video game with which you can build virtual (虚拟的) worlds, will be used in the classroom. Microsoft bought the game Minecraft from its Swedish creator for 2.5 billion dollars. Now, the software company wants to offer schools a special educational version(版本).

    MinecraftEDU is an add-on to the game, which is specially created by teachers for classroom use. While thousands of classes around the world are already using Minecraft in their lessons, Microsoft wants to make it easier for schools to use the software.

    Minecraft is a game that can be used in many subjects, including maths, science and geography. Microsoft wants to add new features to the educational version, for example, letting students take photos and putting them into an online diary. The new version will allow children to download the game at home without having to pay more money for it. Microsoft is expected to ask students and teachers for about five dollars a year to use the game in school and at home.

    According to Microsoft, Minecraft has 100 million players around the world. It has become one of the best-selling games of all time. Pupils can create their own virtual worlds with the help of special building blocks. Joy Morsi, a New York high school teacher, says that Minecraft helps develop the imagination of children in the classroom. Besides, teachers around the world create new things and share them with others, so that the Minecraft community keeps growing.

    Microsoft plans to make the game available to pupils and students of all ages, from primary school to college. The company plans to add Minecraft to an Office 365 account(账户), so that it can also sell more of its Office software.

    In 1901, H. G. Wells, an English writer, wrote a book describing a trip to the moon. When the explorers landed on the moon, they discovered that the moon was full of underground cities. They expressed their surprise to the "moon people" they met. In turn, the "moon people" expressed their surprise. "Why," they asked, "are you traveling to outer space when you don't even use your inner space?"

    H.G. Wells could only imagine travel to the moon. In 1969, human beings really did land on the moon. People today know that there are no underground cities on the moon. However, the question that the "moon people" asked is still an interesting one. A growing number of scientists are seriously thinking about it.

    Underground systems are already in place. Many cities have underground car parks. In some cities, such as Tokyo, Seoul and Montreal, there are large underground shopping areas. The "Chunnel", a tunnel connecting England and France, is now complete.

    But what about underground cities? Japan's Taisei Corporation is designing a network of underground systems, called "Alice Cities". The designers imagine using surface space for public parks and using underground space for flats, offices, shopping, and so on. A solar dome (太阳能穹顶) would cover the whole city.

    Supporters of underground development say that building down rather than building up is a good way to use the earth's space. The surface, they say, can be used for farms, parks, gardens, and wilderness. H.G. Wells' "moon people" would agree. Would you?

, she couldn't sleep well.

We are trying to create a system .