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    Google and Toyota have worked together to create a new smart car. It can run on the road without a driver. It drives itself. The self-driving car hasn't been on sale to the public, so we don't know how much it costs. Another thing most people want to know is whether it will be safe enough to run on the road.

The self-driving car uses electricity (电) as its power, and it can't drive very quickly—the top speed would be 25 miles per hour. It is actually controlled by a computer system on the car. The system keeps on collecting information by some video cameras inside the car and a LIDAR sensor(激光达传器) on top of it. A computer processes the information and decides what to do. "The self'-driving car has only buttons (按钮) for go and stop, so it's very easy to use," an engineer of Google says. "And what's more, it will make car accidents fewer and make the world a safer place." The self-driving car has driven hundreds of thousands of miles in California, and it has only gotten into two accidents by human mistake.

    According to CNN, self-driving cars will also help to reduce the number of cars in big cities. "Self'-driving cars would be able to send you to the workplace and then pick up another person instead of stopping in a parking lot."

    Animals are natural resources that people have wasted all through our history. Animals have been killed for their fur and feathers, for food, for sports, and simply because they were in the way. Thousands of kinds of animals have disappeared from the Earth forever. Hundreds of animals are on the danger list today. About 170 kinds in the United States alone are considered in danger. Why should people care? Because we need animals, and because once they are gone, there will never be any more. Animals are more than just beautiful or interesting. They are more than just a source of food. Every animal has its place in the balance of nature. Destroying one kind of animal can create many problems. For example, when farmers killed large numbers of hawks, the farmers' stores of corn and grain were destroyed by rats and mice. Why? Because hawks eat rats and mice, with no hawks to keep down their numbers, the rats and mice multiplied quickly.

    Luckily, some people are working to help save the animals. Some groups raise money to let people know about the problem. And they try to get the governments to pass laws protecting animals in danger. Quite a few countries have passed laws. These laws forbid the killing of any animal or plant on the danger list. Slowly, the number of some animals in danger is growing.

    There are many wetlands in China and some of them have become the world's important wetlands. The Chinese Yellow Sea Wetlands are among them. They are in Yancheng, Jiangsu Province. They are home to many different kinds of animals. The world's largest Milu Deer Nature Reserve is in them. More than 700 Milu deer live freely there. There are not many red- crowned cranes in the world, but every winter you can see some in the Red-crowned Crane Nature Reserve in the Yellow Sea Wetlands.

    The temperature in the wetlands is usually neither too high nor too low. There is a lot of rain and sunshine too. They are really good places for wildlife. Offering(提供) food and home to some special kinds of animals is not the only reason why we need to protect wetlands. Wetlands are important because they also prevent flood. But some people want to change the wetlands to make more space for farms and less space for wildlife.

    Luckily, more and more people are beginning to realize the importance of wetlands and wildlife. Every year, on February 2nd, many activities are held to tell people more about wetlands.

    If you look at the top of your phone, you'll usually see a little symbol that says 3G or 4G.The "G" stands for the "generation (代)" of your mobile phone network. But these symbols will become things of the past after 5G networks fully arrive.

    On March 30, Shanghai vice-mayor Wu Qing made the first 5G video call on a Huawei Mate X smartphone, CGTN reported. Shanghai has also become the first city in China to start testing 5G networks.

    About 100 times faster than 4G networks, 5G will let people download and upload data faster than ever before. But 5G won't just bring faster mobile Internet. People can use it to do many other things as well.

    For example, 5G will help to make self-driving cars safer. Today's self-driving test cars have one problem-lag (延迟). When the car "sees" an obstacle (障碍物), it sends he information to a data center and receives instructions. However, it takes time to send and receive the information with this kind of lag, the cars might crash because they don't receive instructions in time. With 5G, this lag will be greatly lowered, making the cars safer according to CNN.

    5G could also be used to power the Internet of Things (IoT). This means a large online network that connects all things and people. Fast Internet speeds will be the key to developing this technology. The IoT could be used in a lot of ways. For example, with IoT, your fridge could automatically (自动地) place an order online for eggs when it finds that there are no eggs left.

    The world's first hydrogen-powered(氢动力) trains have begun running in Germany last month. The new trains will run 100-kilometer trips and can travel up to 140 kilometers an hour.

    A French railroad company called Alstom built two hydrogen-powered trains. Teams in Germany and France cooperated on the project, which was supported by the German government. The new train model, called the Coradia iLint, signals the beginning of efforts in Germany and other nations to move away from pollution-producing diesel(柴油) trains.

    Compared(与…相比较) with diesel trains, the Coradia iLint is designed to run on non-electrified train lines with low levels of noise. It uses a process that combines hydrogen and oxygen to produce electrical power. If the system produces more energy than the train needs at that time, it can store the extra energy in batteries. The only emissions(排放物)are water and steam.

    A single tank of hydrogen can run a Coradia iLint train for about 1,000 kilometers. This is very similar to the distance a diesel-powered train can run on with a single tank.

    Hydrogen-powered trains cost more than diesel trains to build. But Alstom officials say the operating costs are much lower. The company plans to provide another 14 Coradia iLint trains by the year 2021. Several other European countries have also expressed interest in developing hydrogen train systems. France has already said it wants its first hydrogen train to be operated by 2022.