What will power your house in the future？Nuclear, wind, or solar power？According toscientists at the Massachusetts Institute of Technology(MIT)in the US, it might beleaves—but artificial(人造的)ones.

    Natural leaves are able to change sunlight and water intoenergy. It is known as photosynthesis(光合作用). Nowresearchers have found a way to imitate this seemingly simple process.

    The artificial leaf developed by Daniel Nocera and hiscolleagues at MIT can be seen as a special silicon chip with catalysts(催化剂). Similar tonatural leaves, it can splitwater into hydrogen and oxygen when put into a bucket of water. The hydrogenand oxygen gases are then stored in a fuel cell, which usesthose two materials to produce electricity, located eitheron top of a house or beside the house.

Though the leaf is only about the shape of a poker card, scientistsclaimed that it is promising to be an inexpensive source of electricity indeveloping countries.“ One can imagine villages in India and Africa not longfrom now purchasing an affordable basic power system based on this technology, ”said Noceraat a conference of the American Chemical Society.

    The artificial leaf is not a new idea. The first artificial leafwas invented in 1997 but was too expensive and unstable for practical use. Thenew leaf, by contrast, is made ofcheap materials, easy to useand highly stable. In laboratory studies, Nocera showedthat an artificial leaf prototype(原型)could operatecontinuously for at least 45 hours without a drop in activity.

    The wonderful improvements come from Nocera's recent discoveryof several powerful, new andinexpensive catalysts. These catalysts make the energy transformation insidethe leaf more efficient with water and sunlight. Right now, the new leafis about 10 times more efficient at carrying out photosynthesis than a naturalone. Besides, the device canrun in whatever water is available；that is, it doesn'tneed pure water. This is important for some countries that don't have access topure water.

    With the goal to “make each home its own power station” and“give energy to the poor”, scientistsbelieve that the new technology could be widely used in developing countries, especially inIndia and rural China.

How to Study Better

    If you want to study better, you should pay attention to learning methods, study skills and study habits. Developing them can help you learn better.

    Keep your study area tidy and organized. Papers, books, magazines, or pictures all over your work area may distract you from the work you have to do. {#blank#}1{#/blank#} If there are too many icons on your desktop, it is difficult for you to find what you need immediately.

    Maintain a quiet work area for yourself. Make sure your work area is free of distractions. There are too many distractions at home, such as a phone, music, TV, friends, or family members. Proper study space can usually be found in the public library, school library, or your bedroom. {#blank#}2{#/blank#}

    {#blank#}3{#/blank#} While learning, you need write, calculate and look up something. So it is very important and necessary to have all the necessary materials and tools that you need with you. In this way, you needn't be busy borrowing them.

    {#blank#}4{#/blank#} In addition to reading your textbook, it is helpful to read or view materials from other sources, such as newspapers, magazines, the Internet, and television programs. You can understand what you will learn in class better.

    Never forget to take notes carefully in class. Taking notes carefully can help to grasp the key parts. {#blank#}5{#/blank#} We can say that it is really a successful way to study.

    If you're showering every day, you're probably over doing it. In fact, showering too often can actually hurt your body in the long run.

    As Time's public health column explains, daily showers are common due to social norms more than any proper health need. We connect being freshly showered with being attractive and pleasing, so we tend to showering often to feel better.

    But what's the ideal shower frequency? In terms of your health — not how you look or smell — probably once or twice a week, assistant professor of dermatology at George Washington University, Dr. C. Brandon Mitchell says. “Your body is naturally a well-oiled machine,” he says. “A daily shower isn't necessary.”

    Of course, your situation may vary. If you have a job like car maintenance or construction, you'll obviously have a visible layer of dirt you'll need to wash off every single day. Similarly, if you work out every day, you may not have any health risks by washing every day, but you'll still be smelly. If you feel like you need to take daily showers for aesthetic（审美的）reasons, at least make most of them light showers. “I tell patients who shower daily not to soap their whole bodies,” Mitchell says. Hit your pits, butt and groin, which are the areas that produce strong smells. The rest of your body doesn't need much soaping, he says.

    Too much time spent under the hot water can dry out your skin, cause cracks（裂纹）that can lead to infections or germs getting into your skin, and take away the natural oils on your skin that help keep it healthy. So, even if you're aiming to be your most presentable, be sure to keep it moderate to avoid hurting your skin in the long run.

    Nowadays everybody seems to think that they know English. Many people speak it but few speak it really well. Practice is necessary in speaking English well.

    Reading is also one of the things that will help you to speak English better. Read whenever you can and whatever you like! Read papers and Internet sites that you like in English every day. Then, you will see that the number of known words is increasing and you are able to speak with more skills. Then you will have made the foundations and a good basis of English. It is not good to stop and get stuck there.

    Going to England or an English-speaking country is a good choice, but many people cannot afford it. If you cannot go, reading and speaking with your friends will also help you to practice your English. However, I think it is very good to visit some English-speaking country to see and test your knowledge in everyday life. You will understand the everyday usage of the language in its natural environment. There your level of English is going to improve even faster. Your ability to speak English is better. Nothing can match the excitement and happiness when a native speaker tells you that your English is very good!

    Finally, in order to speak English well, you must be persistent and do it every day. It is like playing the piano. Pianists play it every day and so should you. Include English in your life and you will see where it is going. Practice, Practice! Read, write and improve your language skills and you are on your way when you will be able to speak it with more and more confidence!

    A team of international scientists is due to set off for the world's biggest iceberg in a mission aiming to answer fundamental questions about the impact of climate change in the polar regions. The scientists, led by the British Antarctic Survey (BAS), are trying to reach a newly revealed ecosystem that had been hidden for 120,000 years below the Larsen C ice shelf.

    Last year, part of the Larsen C ice shelf calved (崩解) away, forming a huge iceberg-A68—which is four times bigger than London, and revealing life beneath for the first time. Now scientists say it is a race against time to explore these new ecosystems before they are transformed to the light. Marine biologist Dr Katrin Linse from the BAS is leading the mission.

    "The calving of A68 provides us with a unique opportunity to study marine life as it responds to a huge environment change," she said. "It is important that we get there quickly before the undersea environment changes as sunlight enters the water."

    Professor David Vaughan, science director at the BAs, said, "We need to be bold (大胆的) on this one. Larsen C is a long way south and there's lots of sea ice in the area, but this is important science, so we will try our best to get the team where they need to be. He said climate change had already affected the sea around Antarctica and is warming some coastal waters. "Future warming may make some habitats warm. Where these habitats support unique species that are adapted to love the cold and not the warm, those species are going to either move or die."

    There is growing concern about the possible impact of climate change in the Antarctic. Earlier this month, a report revealed that melting ice sheets in Greenland and Antarctica are speeding up the already fast pace of the sea level rise. The research, published by the National Academies of Science, Engineering and Medicine, said, "At the current rate, the world's ocean will be, on average, at least 60cm higher by the end of the century." However, it found that the process is accelerating, and more than three quarters of the acceleration since 1993 is due to melting ice sheets in Greenland and Antarctica, the study shows.

    For all the technological wonders of modem medicine, health care-with its fax machines and clipboards (写字板) —is out of date. This outdated era is slowly drawing to a close as the industry catches up with the artificial-intelligence (AI) revolution.

    Eric Topol, an expert in heart disease and enthusiast for digital medicine, thinks AI will be particularly useful for such tasks as examining images, observing heart traces for abnormalities or turning doctors' words into patient records. It will be able to use masses of data to work out the best treatments, and improve workflows in hospitals. In short, AI is set to save time, lives and money.

    The fear some people have is that AI will be used to deepen the assembly-line culture of modem medicine. If it gives a "gift of time" to doctors, they argue that this bonus should be used to extend consultations, rather than simply speeding through them more efficiently.

    That is a fine idea, but as health swallows an ever-bigger share of national wealth, greater efficiency is exactly what is needed, at least so far as governments and insurers are concerned. Otherwise, rich societies may fail to cope with the needs of ageing and growing populations. An extra five minutes spent chatting with a patient is costly as well as valuable. The AI revolution will also enable managerial accountants to adjust and evaluate every aspect of treatment. The autonomy of the doctor will surely be weakened, especially, perhaps, in public-health systems which are duty-bound to cut unnecessary costs.

    The Hippocratic Oath (誓言) holds that there is an art to medicine as well as a science and that "warmth, sympathy and understanding may outweigh the surgeon's knife or the chemist's drug". There's lots of sense in it: the patients of sympathetic physicians have been shown to recover better. Yet as the supply of human carers fails to satisfy the demand for health care, the future may involve consultations on smartphones and measurements monitored by chatbots. The considerately warmed stethoscope (听诊器), placed gently on a patient's back, may become a relic of the past.