WangKun and his sister had dreamed {#blank#}1{#/blank#} taking a great trip since middle school. After {#blank#}2{#/blank#} (graduate) from college, they {#blank#}3{#/blank#} (final) got a chance to make their dream come true. His sister thought of the idea to cycle along the Mekong River from{#blank#}4{#/blank#} it begins to where it ends. They {#blank#}5{#/blank#} bought expensive bikes. They also got their cousins {#blank#}6{#/blank#} (interest) in cycling. WangWei {#blank#}7{#/blank#} (insist) that she organize the trip properly. When she heard that the source of Mekong River is in Qinghai Province, she wouldn't change her mind. She even felt excited {#blank#}8{#/blank#} she knew that their journey would begin at {#blank#}9{#/blank#} altitude of more than 5,000 meters. Before the trip they found a large atlas in the library {#blank#}10{#/blank#} from the atlas they knew clearly about the Mekong River.

    Martin Strel swims with a knife {#blank#}1{#/blank#} (fasten) to his right leg—in case he meets sharks and other {#blank#}2{#/blank#}  (dead) sea life in the world's wildest waters. {#blank#}3{#/blank#} 61-year-old marathon swimmer has announced the {#blank#}4{#/blank#} (tough) challenge of his life: a 10,000-mile-around-the-world journey on water {#blank#}5{#/blank#} (draw) public attention to the increasing water {#blank#}6{#/blank#} (pollute). He aims to circle the globe in about 450 days, passing through oceans, rivers,{#blank#}7{#/blank#} (canal) and other bodies of water in more than 100 countries. He will swim about 5 to 12 hours each day, depending on the weather. A boat will go {#blank#}8{#/blank#} him and offer emergency support and space for small breaks.

    Since 2000, Strel {#blank#}9{#/blank#} (swim) the entire length of five rivers in China, America, etc. Strel will not be alone in the water. He says he welcomes {#blank#}10{#/blank#} is interested in joining him for parts of the route.

    Polar bears are suffering in a {#blank#}1{#/blank#} (warm) world than ever before. Polar bears live in environments too cold for most animals. During much of the year, they live and hunt on the{#blank#}2{#/blank#} (freeze) Arctic sea ice. Nature has prepared them for the cold conditions but nothing has prepared the bears for the danger that {#blank#}3{#/blank#} (threat) the only home they know. The scientists have drawn a {#blank#}4{#/blank#} (conclude) that the polar bears' world is melting. Studies show that the polar ice has reduced{#blank#}5{#/blank#}9.8% every 10 years since 1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their {#blank#}6{#/blank#} (survive). "The sea ice is more than just this platform that the bears walk over." As Andrew Derocher, a scientist who studies North American polar bear populations puts {#blank#}7{#/blank#}, "Only if polar ice melts quite slowly {#blank#}8{#/blank#}they survive on the earth." Some melting and refreezing of the polar ice is natural. {#blank#}9{#/blank#} in a warmer world, these cycles speed up, and bears have less time to hunt. Normally, they have three months in the spring when they gain more weight. The extra fat is used later, {#blank#}10{#/blank#} the bears are not actively hunting.

    Food is one of the most basic and important daily needs. It gives us the strength and energy we need{#blank#}1{#/blank#}(work) and play. Food also plays a role in our social interactions. Whether we{#blank#}2{#/blank#}(celebrate) important occasions or just relaxing with friends, eating is an important social pastime. It is also an important part of our culture.{#blank#}3{#/blank#}a particular people like to eat can tell us a lot{#blank#}4{#/blank#}a country's geography, history and traditions.