Do you like drinking coke, coffee, juice or milk? Do you often drink them instead of water? However, of all the things we eat and drink, water is the most important. Not all of us understand this but it is quite true. Human body can go without food for a long time, but two or three days without water usually makes people die.

    Many people do not understand how much water the human body needs to work well. What is true is that many people do not drink enough, especially in hot weather. Most people drink only when they are thirsty but often need more water after they take exercise.

    Does anyone know what is the 65%-75% of human body? It is water. If we do not have enough water, we will feel tired and become ill. So, do you know what the best drink is? It's water.

    E-waste is fast becoming a serious problem around the world. This report will examine this problem and provide some possible ways to solve it.

We live in a society that is producing and using electronics(电子产品) all the time. It is often cheaper to buy new products than to repair old ones. Also, through clever advertising, companies always encourage people to change their old TVs, mobile phones and computers for the latest models. E-waste is created when we throw away old ones. In the EU alone, about 8,700,000 tons of e-waste is produced each year. Sadly, just over 1,000,000 tons is recycled.

    Burying(填埋) e-waste or burning it cause serious problems for the environment. Electronics have dangerous things in them. These things can then get into the ground or pollute the air when they are burnt.

    In recent years,   ▲  . However, their plans are not always managed properly. Sometimes electronics are just sent to poor countries such as Ghana. Here they are often burnt in public areas, which is very bad for people's health. Setting up recycling centers is a good way to solve this problem. E-cycling centers could recycle the parts that can be reused and deal with the rest properly.

    Another way is to make producers responsible(负责任) for their used products. This means that producers must take back old products which are no longer wanted. They should then make sure they are properly recycled or reused.

    As for us, we should try to cut down on e-waste. Change electronics only when we have to. And don't buy a product just to have the latest model.

    E-waste is a serious problem in the modern world. Both producers and users must take actions and try to keep it to the smallest amount.

    Personal planes which can take off noiselessly from the back garden will be possible within two years.

    Lilium Aviation is inventing an electric two-seater airplane which  takes just 20 hours to learn to fly and can travel at speeds of  250mph.More importantly, the small plane, which weighs just 25kg, can take off vertically which means it does not need to fly from an airport, but could be parked outside a house or in a garden. The company says the design will “open the door to a new class of simpler, quieter and environmentally friendly planes” and will be possible from 2018.

    “Our goal is to develop an airplane for use in everyday life,” said Daniel, CEO and one of the company's four founders. "We are going for a plane that can take off and land vertically and does not need the difficult and expensive infrastructure of an airport.

    Although helicopters offer a choice, they are very noisy and difficult to fly and require expensive licenses. They also have no backup if the rotor fails, making them costly to build and keep. While firstly limited to airfields, the Lilium airplane will eventually take off vertically from almost anywhere – even from back gardens – it needs only an open flat area of 50 ft. by 50ft (15 m x 15m).

    The plane is classed as a Light Sport Aircraft for two users, with the pilot's license requiring 20 hours' minimum training – almost like taking a driving license. It is intended for fun flying during daylight, in good weather conditions and in least crowded airspace up to 3 km altitude. The airplane would have to follow the same flight laws as helicopters.

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    When a computer works on a group of programs, it can get very hot. Cooling the computer can cost a lot. So some scientists wonder what would happen if the heat from the computer could be used.

    Large Internet companies (公司）such as Google and Microsoft have thousands of computers. As these computers deal with information, they produce lots of heat, so they need huge cooling systems(系统）. These systems send the heat into the air.

    A company in Holland(荷兰） thinks paying to make the computers work and then paying again to cool them are a waste of energy. So the company developed a special device—the e-Radiator.

    Boaz Leupe, head of the company, says the e-Radiator works as a heating system and saves money. He explains that the energy is used twice—once to heat the home and once to cool the computer and that the users don't have to pay to cool their computers.

    Five homeowners in Holland are testing the heating system in their homes.

    "We pay for the computer using, so, in that way, homeowners get heating for free," Boaz says.

    Jan Visser is one of the homeowners. "If you use the computer more, the e-Radiator produces more heat," he says. "It can't provide enough heat if you don't use your computer often." But he is ready to try it. It's a great help for his family.

    The company says e-Radiators produce heat temperatures of up to 55℃. It says the system could save its users about $440 a year.

    Space vegetables are grown from seeds(种子) that have been taken to space and brought back to the earth. The seeds are affected by the radiation(辐射)and low gravity in space. When they are brought back to the earth, these seeds produce vegetables that are bigger and healthier than normal vegetables. However, some people worry about eating space vegetables. They think that space vegetables might not be good for us and could make us get sick because of the radiation in space. However, people should not be frightened because space vegetables are very healthy.

    Here are some facts that you should know about space vegetables.

Space vegetables are grown from seeds that are carefully chosen. When seeds are brought back from space they are tested to make sure that they will be safe to eat.

    Space vegetables are better for you than normal vegetables. For example, space tomatoes stay fresh for twenty days, which is one week longer than normal tomatoes。

    After genetically modified (转基因)food appeared in the market, people worried that they were eating unknown things. For example, if nut genes(坚果基因) are put inside potatoes, people allergic(过敏的) to nuts might get sick from eating these potatoes because they do not know they are also eating nuts. Unlike genetically modified food, space vegetables have not been genetically changed. This means that no new genes are put into the vegetables. Therefore, there are no dangers of eating unknown.