Our warming planet is expected to face serious water crisis（危机）in the coming decades — which means each nation's natural resource will be more important than ever.

    Even before my father left us, my mother had to go back to work to support our family. Once I came out of the kitchen, complaining, "Mum, I can't peel (去皮)potatoes. I have only one hand. "

    Mum never looked up from sewing. "You get yourself into that kitchen and peel those potatoes," she told me. "And don't ever use that as an excuse for anything again!"

    In the second grade, our teacher lined up my class on the playground and had each of us race across the monkey bars, swinging from one high steel rod to the next. When it was my turn, I shook my head. Some kids behind me laughed, and I went home crying.

    That night I told Mum about it. She hugged me, and I saw her determined look. The next afternoon, she took me back to school. At the deserted playground, Mum looked carefully at the bars.

    "Now, pull up with your right arm," she advised. She stood by as I struggled to lift myself with my right hand until I could get the bar with my other elbow (月寸）.Day after day we practiced, and she praised me for every rung (梯级）I reached.

    I'll never forget the next time, crossing the rungs； I looked down at the kids who were standing with their mouths open.

    One night, after a dance at my new junior high, I lay in bed crying. I could hear Mum came into my room. "Mum," I said, weeping, "None of the boys would dance with me."

    For a long time, I didn't hear anything. Then she said, "Oh, honey, someday you'll be beating those boys off with a bat." Her voice was slight and cracking. I looked out from my covers to see tears running down her cheeks.

    Then I knew how much she suffered on my behalf. She had never let me see her tears.

    The British are known for their sense of humor. However, it is often difficult for foreigners to understand their jokes. The main point to remember is that the British often use understatement.

    Understatement means saying less than you think or feel. For example, if someone gets very wet in a shower of rain, he might say, "It's a little damp (潮湿的) outside." Or, if someone is very impolite and shouts at another person, someone else might say, "She isn't exactly friendly." Understatement is often used in unpleasant situation or to make another person look silly. Understatement plays an important part in British humor.

    Another key to understanding British humor is that the British like to make fun of themselves as well as others. They often laugh about the silly and unpleasant things that happen to our everyday life when someone accidentally falls over in the street. They also like to make jokes about people from different classes of society. They like to make jokes about their accents, the way they dress and the way they behave. What's more, the British love to watch comedies (喜剧) about people who do not know how to behave in society. The comedies series Mr. Bean is a good example of this kind of humor.

    Mr. Bean is the character created by British actor Rowan Atkinson in 1990. Mr. Bean doesn't talk often, and instead he uses his body movement and facial expressions to make people laugh. Perhaps what makes Mr. Bean so funny is that he does things that adults in the real world cannot do. Mr. Bean is popular in many countries around the world because you do not have to speak English to understand the humor. Because of this, many people have become familiar with the British sense of humor.

    Every summer, my family and I visit our relatives in India and whenever we travel, my parents always remind me to drink only bottled or boiled water. On one of my trips to India, I saw children drinking water from the roadside. I was troubled to learn that millions of people, most of them children in developing countries, die each year because of water related diseases.

    Living in the US, I am lucky to be able to turn on the tap and get potable water(饮用水), while one sixth of the world's population lacks access to clean water This year, I entered the Discovery Education 3M Young Scientist Challenge. In late June, I learned that I was selected as one of the top 10 national finalists of this famous middle school science competition. Over the summer, I worked with Dr. Jim Jonza, my Scientist mentor(导师 )from 3M, and developed a system that uses solar energy to purify water. My invention is green and cost effective, and I am looking forward to implementing this in places that are affected(影响)by harmful water pollution.

    In October, my family and I flew to 3M Headquarters in St Paul, Minnesota, where the final event was to be held. For the last challenge, each of us had to present the invention we had been working on over the summer. The first place winner would win $25,000, a trip to Costa Rica, and the title of America' Top Young Scientist. At the awards ceremony, all of us waited anxiously until one of the judges, Danny Forester, started announcing "The winner of the Discovery Education 3M Young Scientist Challenge is…" You could hear a pin(大头针) drop as he opened the paper with the winner' s name, "Deepika Kurup!"

    As America's Top Young Scientist, I was given an opportunity to show my invention on national television and deliver several presentations. One of the most important things I have learned is that communication and teamwork are key to success.

    A project in Gambia is empowering women and reducing dangerous waste at the same time.

    The Waste Innovation Center, funded by the European Union's Global Climate Change Alliance, shows women in the Brikama area how to recycle waste into useful materials and products, which they can then sell in local markets.

    Wood-like waste is recycled into charcoal (木炭), for example, which can be used to supersede firewood and reduce the number of trees that are cut down for firewood. Food waste is recycled into compost(混合肥料)to function as environmentally friendly fertilizers and plastic is turned into many useful things.

    Supported by Waste Aid UK and the Gambia Women's Initiative (GWI), among others, the project provides women with skills they can use to become self-sufficient (自给自足的). Women learning at the center come from five communities, and some of them travel as far as 12 miles to learn these important skills that will provide them with an income, according to The Guardian.

    Isatou Ceesay, who now leads the GWI, highlighted the need to focus on economic equality in her country, telling The Guardian, "In terms of education, women are the ones who are always behind. Boys are chosen to go to school. When we conduct our training, we find women can do a lot, but don't know who they are, or how to carry out things. "

    According to the World Health Organization's Country Cooperation Strategy 2018—2023 report, the main environmental issue facing Gambia is poor waste management in urban areas. Ndey Sireng Bakurin, executive director of the National Environment Agency, has voiced concern over health and environmental risks, such as water pollution, the increase of insects as well as flooding that occur as a result of poor waste management.

Gottfried Wilhelm von Liebniz was a philosopher and mathematician in search of a model. In the late 1600s Leibniz decided there was a need for a new, purer arithmetic than our common decimal (十进制) system. He got his inspiration from the 5000-year-old book that is at the heart of Chinese philosophy: the I-Ching, or Book of Changes.

This ancient text was such an influence on Liebniz that he titled his article on the new arithmetic "Explanation of a new arithmetic and the ancient Chinese figure of Fu X". Fu Xi was the legendary first author of the I-Ching. The arithmetic that Liebniz described was binary (二进制) code, which is used in almost every modern computer, from iPhones to China's own Tihane-2 supercomputer.

To figure out what Liebniz learned in the I-Ching, we need to understand something that most of us have taken for granted. When we listen to an MP3, look at a digital photo or watch the latest TV drama, we are experiencing a digital representation of reality. That representation is basically just a string of binary signals that are commonly known as 1s and 0s. What Liebniz's gained from the book was that even the most complex reality could be represented in the binary form as 1s and 0s.

In the philosophy of the I-Ching, reality is not entirely real. It is something more like a dream. This dream of reality arises from the binaries of Yin and Yang, as they play out countless combinations, practically everything in the universe. It's not surprising then, from the l-Ching's perspective, that anything in the dream of reality can be represented in a string of 1s and 0s, processed by a computer.

The I-Ching was far more ambitious than the current practical applications of binary code. It is claimed that the I-Ching represents nothing less than the basic situation of human life itself. As a system for predicting the future, the I-Ching might disappoint, but as a way of questioning your own unconscious mind, it can be remarkably useful.

The I-Ching's teachings also contain warnings about our digital revolution. Binary code, powered by modern computers, has an amazing capacity to represent reality. However, the ancient authors of the I-Ching might have understood its potential-and its dangers-even better than we now do.

So when scientific thinkers ask whether computers can create "virtual realities" or "artificial intelligence", they are missing the point. Of course, we can create ever deeper and more complex layers of the dream of reality. The real question is, can we wake up from the dream we're in already?