Smog is a big problem in many Chinese cities. But it seems that besides wearing a mask, few of us know what has caused the smog and what to do to beat it. In fact, burning too much coal and oil are the main causes of PM2.5 and smog (雾霾).

    To solve the problem, we should clean our coal and oil or replace them with cleaner energy such as natural gas. We ordinary people can do something to help control smog, too.

    What can we do to help beat the smog?

    Choose to take public transportation. Though many people have their own cars, they had better take public transportation, such as the subway or buses. If the destination (目的地) is not far away, you can also walk ________ ride a bike.

    Call the hotline 12369. You can call the number for complaints and questions about environmental issues. It is run by China's Ministry of Environmental Protection. If you call the number, some officers can come and try to solve the issues, so please remember it.

Report and resist pollutant source. If you find any pollutant source, take a picture of it and post it on your social media accounts. Remember to add “@local environmental departments” on weibo. Payattention to factories that pollute the environment and don't buy products from them.

    Our environment will become better if everyone is concerned (关注) with the environment. This is what we need in the future. So everyone can do something to beat smog.

    There are all kinds of horses in the world. But one of them you can't ride. It doesn't live on land, but in the sea. Its head looks like the head of a horse .So people call it a "sea horse." In fact, The sea horse is a small fish. It likes to live in warm water. A sea horse always stands up in the water when it swims.

    The mother sea horses give eggs, but they put the eggs inside   father's body to keep them safe in its pouch until they hatch()孵化. When the eggs are hatched after 40 to 50 days, the baby sea horses swim away.

根据短文内容，选择正确答案。

    In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.

    Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating (挨打) and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.

    Until now, even the most advanced (先进的) robot was almost certain to break down when it was damaged. That is because its computer inside simply doesn't know how to make the machine work after its shape has changed.

    To deal with this problem, the scientists put eight motors (发动机) and two sensors (传感器) that read how the machine is working. They all give signals to the machine's software. Using this information, the computer can then figure out the machine's shape at any moment.

    The new technology is a big advance in robot-making, scientists say, and it's far from scary. It may someday help scientists create better artificial (假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.

    “It has been difficult to design robots that can work well when the environment changes or when it's damaged,” says Olaf Sporns of Indiana University in US. “With this work, we are nearer to solving this problem.”

    The days of having to carry a phone charger(充电器) everywhere could soon be over. Researchers from America have made great progress in getting energy from human motion(运动). They say smartphones could get enough power just by the motion of fingers on the screen.

    The low-cost device(装置) has already been tested in an American university. Scientists successfully showed an LED touch screen, a total of 20 LED lights and a keyboard, all with a simple touching or pressing motion and without the help of a battery.

    "What I predicted is the possibility of not having to charge your smartphone for a whole week, for example, because that energy will be produced by your motion," said one of the researchers.

    The completed device is as thin as a piece of paper. Electrical energy is created when you press it. The device used to power the LED lights is the size of a hand while the device used to power the touch screen is as small as a finger.

    The device will become more powerful when folded. Each time you fold it, the energy you create will be doubled. You can start with a large device, but when you fold it once, and again, and again. It's now much smaller, but it has more energy. It may be small enough to put in a specially made heel(脚后跟) of your shoe so it can create power each time your heel knocks the ground. The researchers are also developing technology that would send the power produced from the heel strike to an earphone.