E

    The Earth is our home; we must take care of it. This means keeping the land, air and water clean. Pollution is a dirty word. To pollute means to make things unfit or unclean to use. Pollution comes in many ways. We see it, smell it, taste it and drink it. Pollution is beginning to threaten (威胁) our health, our happiness and our life. Man has been polluting the earth from the time he first made fire, washed his clothes in the river and threw his waste on the ground. When land was used up or water became dirty, men moved on to another place. At first, the problem was not so serious because there was plenty of clean air, land and water. There weren't so many people then and their wants were fewer. All the dirty things could be absorbed (吸收) by nature and soon covered over. But this is no longer true. The increase of population and the development of industry(工业)have changed that. Man is slowly poisoning (毒害) his environment. Through the use of poison, man has polluted the land, killing the animals. By putting dirty water and chemicals into rivers and lakes we have polluted our drinking water, killing the fish.

    Our increasing population is part of the problem. More people, more waste.

    Where is this all to end? Are we turning the world into a big rubbish dump (堆存处), or is there any hope that we can get rid of (摆脱, 除去) the pollution? Luckily, millions of people have been warned of the danger of pollution. Large numbers of people are now working hard to bring pollution under control.

根据短文理解，选择正确答案。

    Imagine the situation. You are driving along a desert or on a mountain. You have no idea where you are. You passed the last house two hours ago. Then your car breaks down. It is night and it is cold. You have no mobile phone. What do you do? Well, next time take a GPS with you. This invention may be able to help you. It is a device(装置) which uses satellites (卫星) to find the user's position(位置). It can find your position to within 20 metres. A GPS cannot start your car, but at least you will know where you are.

    GPS, which means Global Positioning System, is a small radio receiver. It looks like a mobile phone. You can hold it in your hand, or put in your pocket. It is sometimes put into a watch or a telephone. We also find GPS devices in cars, planes, or boats. Some of these devices have electronic maps, so you know where you are. For example, in a city they can tell you the name of the street.

    There are three parts to the Global Positioning System. The first part is the receiver. You can hold it in your hand, or have it fixed into your car, plane, etc. The second part is a group of satellites orbiting the Earth. The receiver contacts at least four of the satellites and calculates(计算) its position. The third part of the system is a network of ground stations. They are all over the world. They control the satellites and make sure they are working well.

    Some people think that in the future the GPS will be as common as the mobile. They are becoming cheaper and more and more accurate(精确的). There are also new uses for the GPS. Perhaps they will become like watches. Everyone will have one and you will never be lost again.

B

    EVERYDAY since March 8, people all over the world are repeatedly asking the same question: Where did Malaysia Airlines Flight MH370 go? It turns out to be the saddest answer.

    On March 24, Malaysian Prime Minister(总理) Najib Razak announced that the plane "ended in the southern Indian Ocean". All 239 people on board, including 154 Chinese, died.

    The conclusion was based on satellite(卫星) data from the British Air Accidents Investigation Branch and Inmarsat, a Britain ­based satellite company. No debris(残骸)of the plane had been found.

    The news sent people, especially families of passengers(乘客), into deep sorrow. They are asking for more details about the investigation.

    China has already asked Malaysia to provide(提供) all the information and evidence(证据) leading to the conclusion, said Chinese Foreign Ministry spokesman Hong Lei. He said China would continue with their search effort. "We hope that other countries will also continue their search, " Hong said.

D

    It is reported that some developed countries have shipped broken parts of computers to China. Last month Hong Kong officers found 131,000 kilograms of broken computers, TVs and phones sent from Japan.

    Things like these are called electronic waste, or e-waste. Dealing with them is not an easy job. Every time an old computer breaks down, it needs to be dealt with safely. What is worse, at present, broken computer parts are usually buried. It may be hundreds of years before they are really g one in the earth.

    Many places in China are polluted by e-waste. Guiyu in Guangdong Province is one of them. This town is named as "the e-waste capital of the world". It has to deal with 1.5 million kilograms of e-waste each year, from which it makes 75 million yuan. But it comes at a cost. Many of the poisons in e-waste find their way into the environment. An environmental group has found the air, the earth and the rivers in Guiyu badly polluted.

    Luckily, the Chinese government wants to change the situation. This year, China passed a new environmental protection law. Computer companies like Lenovo and Dell will be asked to take back their old computers. Hopefully, the problem with e-waste will be solved in the near future.

    Shanghai University of Engineering Science has become the first university in China to be covered by a 5G network, the university announced on Tuesday.

    Chinese mobile carriers(运营商) are expected to spend 1.2 trillion yuan（US＄176.5 billion） on 5G by 2025,50 percent more than their total 4G investment (投资), Nomura said yesterday. Carriers including China Mobile, China Telecom and China Unicom, are expected to build over 4.9 million 5G base stations by 2025.

    5G is a" game﹣changing" opportunity for carriers as they can explore new business like smart manufacturing, super high definition video and smart driving, instead of just being a "pipeline" for voice and data services.

    China will supply "temporary "5G licenses in several aimed cities this year. Consumers(消费者) will be able to use the first batch of 5G smart﹣phones and tablet computers in the second half. It's the first time that China's top industry regulator clarified the 5G industry timeline, especially the first appearance of 5G phones.

    But 5G services will become accessible to normal consumers later than expected. More work needs to be done to make the 5G industry fully developed, which won't happen until 2020, said UBS recently. New business projects and organizations, rather than normal consumers, will enjoy 5G services at first. The first batch of 5G services will be available to consumers in about 10 cities only.

    The biggest secret about inventing is that anybody can do it! Perhaps this sounds crazy, but it's true. Maybe you have the wrong idea about inventing, so read on to discover the truth.

    Wrong idea No. 1: An invention has to be something completely new.

    Inventing means creating something "new", but the idea could come from something that already exists(存在). The Wright brothers, for example, got the idea for building a "flying machine" from watching birds.

    Wrong idea No. 2: Inventors are born, not made.

    There are a lot of factors(因素) that make invention possible. Take Mazart, for example. He was born with a talent for musical composition. But other factors were also important for his creativity. His father was a music teacher, and Mozart practiced for hours every day, from the time he was four years old. Thomas Edison said that being an inventor was "99% hard work and 1% inspiration"!

    Very successful creators don't give up when they get something wrong. As one inventor said, "A failure is the right answer to the wrong question."

    Wrong idea No. 3: Inventors are always old people.

    Don't believe that you can't invent something when you are young. Here are two examples of young inventors: Louis Braille went blind when he was a child. When he was fifteen, he invented a system of reading and writing for blind people that is still used in most countries today.

    As a young man, George Nissen was watching some artists performing in a show. He watched how they fell into the safety net and then jumped back up again. This gave him an idea, and he invented the trampoline(蹦床).