Don't be surprised if you see a car going down the road without a driver in Beijing these days.In march, 2018, baidu was given a license to test its self-driving cars in Beijing, China Daily reported.

    Self-driving cars have been in development since 2010, when google announced that it was making such cars. Since then, companies like Tesla, Uber and Baidu have been working to produce and test their own self-driving cars.

    Self-driving cars are expected to change the way we get around. They are safer and more environmentally friendly than regular cars. They can remove the stress(压力) of driving and allow disabled or blind people to get around more easily.

    But self-driving cars have their own disadvantages as well. In one test, researchers pointed a laser pointer（激光棒） at the car's sensors（感应器） while it was moving. The car mistakenly thought that the laser beam（波束） was in its way and slowed down or changed directions.

    The software(软件) that is used to direct the cars may not be safe enough. Reported Live science. Sometimes, without any reasons,it may break down when we use our computers or smartphones. If the software in a self-driving car happened to crash. The results could be deadly.Maybe improvements to the software could solve this problem.

    Apple has created a new robot named Daisy that can break a dead iPhone into pieces and find out valuable materials such as silver and tungsten (钨) in order to protect the environment.

    The robot can break up a dead phone in just 18 seconds and is a new type for Liam, another recycling robot Apple announced in 2016. Liam had 29 arms and could break iPhone into pieces within just 11 seconds.

    Daisy is able to break up 9 kinds of the iPhone, grouping them into usable parts. And it can find out valuable materials that traditional robots can't do.

    Without being stopped. Daisy is likely to do with over 1 million phones per year, a small part of the more than 2017 million phones Apple sold in 2017. The machine is programmed to carefully break up the many pieces of returned iPhones, including SIM card plates, batteries and cameras.

    It does this by taking away different parts of the iPhone bit by bit so they are all easier to recycle, separating out the valuable silver, tungsten and other parts. Computers made by other companies seem to be easier to break up. However. Apple does not make it public how many of its dead phones are recycled every year.

    As space science develops, man has learned more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.

    Scientists have found out that the radiation(辐射) is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of the radiation from the sun and other stars, which is bad for their health. The harm of the radiation won't be found until their children even grandchildren are born. Some special medicine may work a little, but no really effective medicine has been found so far. Space rubbish is also thought to be a great danger to spacemen. It's reported that there were 9,000 man-made things flying in space. About 30% of these are satellites, 10% are spaceships, and the rest are space rubbish. An explosion(爆炸) in space in 1999 made a cloud of 300,000fragments, each at least 4mm in size. A small piece of these even knocked a spaceship window and caused some damage(损坏).

    Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish. Although space is really dangerous, it interests many people on the earth. In the near future, it may become possible for people to spend a few days in a space hotel. People may even choose to leave the earth and live in space in a few years. So scientists are doing everything they can to help improve the space environment.

    A few years after World War Ⅱ finished, scientists spoke with great eagerness about the use of nuclear power as a source of energy. Within twenty years, they said, nuclear would take the place of coal, gas and oil as a source of power at home and in industry. This promise has never been carried out(兑现)and there are serious doubts that it ever will be. Nuclear power plants are used to produce energy in some wealthier countries, but the cost is high.

    Although safety measures have been taken, radiation leaks have taken place and workers have been killed or affected. The problem of getting rid of the nuclear waste has proved most difficult. There is a limit to the amount of waste materials which can be buried in the ground or poured on the sea-bed. These methods may also cause more problems. Waste materials polluted by radiation may remain dangerous for 200 years or more.

    It is no surprise that scientists have now turned to the sun and the sea as sources of power. The sun shines day after day almost wastefully, providing us with energy far be yond all our needs.

①Franz Schubert was a music giant (巨匠). He wrote several symphonies (交响乐) and operas, about600 songs, and had many other musical works.

②Schubert was born in a musical family in Vienna on January 31, 1797. His father was a teacher, and he taught young Schubert to play the violin. One of Schubert's brothers also gave him piano lessons. Schubert was really good at writing all kinds of music. Schubert started working at his father's school in1814, but he didn't like teaching. So he spent most of his free time writing music. During that time, he wrote his first full symphony and opera. He also wrote many famous songs.

③In 1818, Schubert gave up teaching to make music full time. It was a good change. People liked his music, and they even paid him to write music for them. Schubert finally made money from his musical works, but they didn't make him rich.

④Schubert died at the age of 31 on November 19, 1828. Schubert and his music were popular during his time. And people still listen to his music today.