Diets have changed in China-and so too has its top crop. Since 2011,the country{#blank#}1{#/blank#}（grow）more corn than rice. Corn production has jumped nearly 125 percent over{#blank#}2{#/blank#}past 25 years, while rice has increased only 7 percent.

    A taste for meat is{#blank#}3{#/blank#}(actual) behind the change. An important part of its corn is used to feed chickens, pigs, and cattle. Another reason for corn's rise. The government encourages farmers to grow corn instead of rice{#blank#}4{#/blank#}(improve) water quality. Corn uses less water{#blank#}5{#/blank#}rice and creates less fertilizer(化肥) runoff. This switch has decreased{#blank#}6{#/blank#}(pollute) in the country's major lakes and reservoirs and made drinking water safer for people.

    According to the World Bank, China accounts for about 30 percent of total{#blank#}7{#/blank#}(globe)fertilizer consumption. The Chinese Ministry of Agriculture finds that between 2005-when the government {#blank#}8{#/blank#} (start) a soil-testing program {#blank#}9{#/blank#} gives specific fertilizer recommendations to farmers - and 2011, fertilizer use dropped by 7.7 million tons. That prevented the emission(排放) of 51.8 million tons of carbon dioxide. China's approach to protecting its environment while {#blank#}10{#/blank#} (feed) its citizens "offers useful lessons for agriculture and food policymakers worldwide." says the bank's Juergen Voegele.

    Can you imagine the world full of crying and shouting, covered in darkness? However, it's not just a joke. It's a real {#blank#}1{#/blank#} (describe) of a world without happiness and laughter.

    If you compare our life to a pie, what would you put in if you were in charge of making the pie?{#blank#}2{#/blank#} (obvious), many people would add as much happiness as possible. Do you know why? It's {#blank#}3{#/blank#} happiness stands for sweetness in most people's minds.

    Don't think of it just as a comparison. Happiness is a flower {#blank#}4{#/blank#} (live) in the sunshine, and it is not difficult to reach for it. We have a variety of {#blank#}5{#/blank#} (emotion) like sadness, anger, fear, enthusiasm and happiness, and they all appear naturally when something {#blank#}6{#/blank#}(affect) our feelings. So, if we can change our attitude {#blank#}7{#/blank#}things in the world, we can certainly adjust our emotions. It means that we can choose to be happy if we want to, as long as we view everything in {#blank#}8{#/blank#} positive way.

    If we can be happy, why not {#blank#}9{#/blank#}(choice) to be? Let's try together to create a world {#blank#}10{#/blank#}(fill) with smiling faces and sunshine.

    Before the 17^th century, most of the native English speakers lived in England. After the 17^th century, British people began to move to other {#blank#}1{#/blank#} (country). Gradually, English was spoken there. At present {#blank#}2{#/blank#} (many) people speak English as their first, second or a foreign language than ever before. {#blank#}3{#/blank#} (luck), native English speakers can understand each other even if they don't speak the same kind of English.

    English {#blank#}4{#/blank#} (change) and developed when cultures met and communicated with each other over the past centuries. The English {#blank#}5{#/blank#}(speak) in England between about AD450 and 1150 was very different {#blank#}6{#/blank#} the modern English we speak today. It was the new settlers that enriched the English language and {#blank#}7{#/blank#} (especial) its vocabulary. The English language was settled by the 19^th century {#blank#}8{#/blank#} two big changes in English spelling happened. English now is also spoken as a foreign {#blank#}9{#/blank#}second language in South Asia. China may have the {#blank#}10{#/blank#} (large) number of English learners.

    In the 1980s, Paolo Dario dreamed of developing {#blank#}1{#/blank#}(high) advanced artificial limbs(假肢) to help people who really need such devices(设备), but he never expected his dream to be realized. Dario, {#blank#}2{#/blank#}professor of biomedical robotics in Italy, said that as an engineer he always wants to see such dreams come true, even if a lot of work must {#blank#}3{#/blank#} (do).

    He {#blank#}4{#/blank#}(make) the comment(评论) in Beijing last month during a keynote speech at the 2019 World Robot Conference." You have to understand the {#blank#}5{#/blank#}(exist) problem and develop robotic arms by thinking outside the box. We hope what we need for robots can become smaller and lighter. But at the same time, as a lot of technology is now used in robotic sensors (传感器), they have become much {#blank#}6{#/blank#}(large)," he said.

    A paper {#blank#}7{#/blank#}was published in the journal Nature in 2014 stated that a human can not only control artificial limbs, {#blank#}8{#/blank#}feel the different materials they are made from as well." In the future, the super robot will further enable people with disabilities to walk on {#blank#}9{#/blank#}(they) own and allow blind people {#blank#}10{#/blank#}(recover) their sight," Dario said.