In recent years, learning Chinese{#blank#}1{#/blank#}(become) popular among people around the world. Last month, I received an email from my cousin Jack in Canada. He said he was enthusiastic{#blank#}2{#/blank#}Chinese, and asked me to find him some books{#blank#}3{#/blank#}(intend) for Chinese beginners. I was very pleased to do{#blank#}4{#/blank#}a favor. So I went from one bookstore to{#blank#}5{#/blank#}, hoping to find something suitable for him.{#blank#}6{#/blank#}（final） I selected a set of Chinese textbooks among {#blank#}7{#/blank#}(vary) similar ones. Then I went to a post office to have them delivered by air without delay. Several days later, I received Jack's email,{#blank#}8{#/blank#} (say) that he really appreciated the books I had sent. I'm very glad that Jack is beginning to learn Chinese just like many other{#blank#}9{#/blank#}(foreign) abroad,{#blank#}10{#/blank#}I know it may be an enjoyable challenge for him.

    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.

    The earth was just {#blank#}1{#/blank#} cloud of dust after the “Big Bang”. The earth exploded {#blank#}2{#/blank#}(loud) with fire and rock. They were in time to produce carbon, nitrogen, water vapour and other gases, which were {#blank#}3{#/blank#}(make) the earth's atmosphere. As the earth cooled down, water began to appear on its surface. It allowed the earth to dissolve {#blank#}4{#/blank#}(harm) gases. Then life began to develop.

    Small plants multiplied and filled the oceans and seas with oxygen. This encouraged the {#blank#}5{#/blank#}(develop) of early shellfish and fish. Land animals such as insects, reptiles and dinosaurs {#blank#}6{#/blank#}(appear) after green plants came into being. Small clever animals spread all {#blank#}7{#/blank#} the earth. They are putting too much carbon dioxide into the atmosphere, {#blank#}8{#/blank#} prevents heat from escaping from the earth into space. {#blank#}9{#/blank#} life will continue on the earth for millions of years to come will depend on whether this problem can {#blank#}10{#/blank#}(solve).

    Newton made important contributions to every area of the scientific and mathematical concept to his generation. Born in {#blank#}1{#/blank#} rural English village on Christmas Day, 1642, he was so small that no one thought he would survive. During his childhood he spent much of his time inventing and building toys, and did not do particularly {#blank#}2{#/blank#} (good) at school. So his mother, who was {#blank#}3{#/blank#} (will) to pay for his education, brought him home to look after the sheep. However, he was always so busy {#blank#}4{#/blank#} (build) small devices that the sheep would often escape. Eventually his uncle persuaded his mother {#blank#}5{#/blank#} (send) him to the University of Cambridge, {#blank#}6{#/blank#} he became so absorbed in his studies that he often forgot to eat or sleep.

    When Cambridge was closed for two years due to the plague(鼠疫), Newton went home to work on his studies. He {#blank#}7{#/blank#} (bury) himself in mathematics and began developing a mathematical theory that would later become calculus(微积分). It is a popular belief {#blank#}8{#/blank#} on one occasion he was sitting under an apple tree {#blank#}9{#/blank#} an apple fell on his head, which helped him to understand the laws of gravity. It is now thought that perhaps he invented this story in later field to explain how he drew his {#blank#}10{#/blank#} (inspire) from everyday events.