A hobby can be almost anything that a person likes to do in his free time. Hobbyists raise pets, watch birds, paint pictures, play the piano and grow flowers. They also go to concerts, climb mountains, go fishing, skate and swim. They collect everything from books to butterflies and from boxes to stamps.

    People follow hobbies because these activities offer enjoyment, friendship，knowledge and relaxation. Sometimes they even make money by following a hobby. Hobbies help people relax after hard work, and provide a balance between work and play. Hobbies also offer interesting activities for persons who are retired. Anyone, rich or poor, old or young, can follow an interesting hobby.

Hobbies can also help a patient to keep healthy. Doctors have found that hobbies are useful in helping patients (病人) recover from illness. Hobbies give patients who can't move around something to do, and provide interests that keep them from thinking about themselves. Many hospitals treat (治疗) patients by having them take up interesting hobbies. Anyone, old or young, sick or well, rich or poor, can follow a good hobby, in spite of his age, health or money.

    In early times, most people were too busy making a living to have many hobbies. But some persons who had spare time did enjoy hobbies. People today have more time than ever before for hobbies. Machines have now reduced much time that people must spend on their jobs. More people retire at an earlier age than before. Those who have developed hobbies never need to worry about what to do with their newly-found free time hours.

    Sir William Osler, a famous Canadian doctor expressed the value of hobbies by saying, “No man is really happy or safe without a hobby. ”

    Sheridan is a town in Indiana, USA. There are lots of trees near the public schools in the town. Their leaves turn sunlight into energy.

    In Sheridan, the Sun not just provides energy for plants. It keeps schools running, too. The schools use solar panels(太阳能电池板) to turn sunlight into energy.

    The science behind solar energy is not new. But Sheridan Community Schools is the first school district (学区) in Indiana to be completely solar-powered. The district finished putting in solar panels for all three of its schools in 2016. Some of the panels can turn to follow the Sun across the sky.

    In 2008, fewer than 1,000 schools used solar power. By 2014, there were 3,727 schools with solar panels in the USA. These numbers come from a report by The Solar Foundation. Roxie Brown, a programme director there, said that the number of schools with solar panels has continued to go up since 2014.

    Solar energy has some advantages over other energy sources (来源). Sunlight is a renewable source, which means it won't run out. Solar panels don't harm the environment. Also, sunlight is free. So by using solar power, schools can save money on energy costs. Brown thinks more schools should run on solar energy. "The Sun is Earth's energy source," she says. "We're trying to make it the energy source for our houses, cars and schools, too."

    But using solar energy isn't always easy. Solar panels can be expensive to put in. The panels also take up space. But for many schools, going solar is worth it.

    What will our homes be like in the future? Here are some predictions:

    Want to take a shower when you get home? You'll be able to let your smart water heater(热水器) to start heating up when you're on your way home..

    Did I turn off the oven? Did I close the window? Everyone may have a moment like that. But in the future, your home will check these for you.

    In your home of the future, all of your devices (设备) can work together to make your life more comfortable. When you turn on the lights in the morning, your windows will open at the sometime. The lights will slowly turn off by themselves after the sun appears.

    Your home may have dangers. The hackers (黑客)could open your door and cause a mess at your home through your phone or other devices. Your home will tell you about it, but you can't arrive in time. So people will have to be careful of their personal information.

    As everyone knows, animals are our friends. Of all the animals, dogs are friendly to 1.

    Dogs are always staying 2 human beings. They are in different colours. There are many different 3 of dogs. Hunting dogs can 4people get more prey(猎物). The seeing-eye dogs can help 5people a lot. The police dogs can help the police.

    Today it is 6 to imagine the life without dogs. Maybe everyone is happy to see dog. Dogs are good at7 and smelling. Some dogs can find the people who are trapped(困) 8 the broken house. Some dogs can help take care of the houses. 9someone strange comes close to the house, they will bark to frighten him. Even some dogs can help look after kids when their 10 are not at home.

    In a word, dogs are our best friends among all animals.

    Uber (优步)announced that it plans to invest 20 million in developing an aircraft in France over the next five years.

    It will open a new research and development center in Paris﹣its first technology hub outside of North America.

    "France is a perfect home for our next step forward with its strong history of research and development, world class engineers and a unique role in aviation (航空)worldwide,"Uber said in a statement.

    Uber already has R & D offices in Pittsburgh, Toronto, and San Francisco. They focus mainly on Uber's self﹣driving technology, but have also been working on Uber's Elevate flying car program.

    The Advanced Technologies Center in Paris will open later this year and only focus on flying cars. It will conduct research into airspace management, real﹣time communication networks, energy storage, and charging systems.

    Uber's announcement, made at a tech meeting in Paris, has been supported by French President Emanuel Macron, whose ambitious economic reforms are to attract more foreign investment.

    The company also announced a five-year research partnership with Ecole Polytechnique, a leading French institute of technology.

    Uber has been working on its flying car program since 2016. NASA became a partner for the program a year later by developing air traffic management for a fleet of flying cars.

    Uber expects flight to become a daily part of our transportation lives. The company believes it can offer rides in flying cars for about the same price as an Uber X ride. This technology may completely change our transportation lives in the future.