Way back in 1674, a frog helped Antoni van Leeuwenhoek make an incredible discovery. Antoni was an amateur scientist from Holland, so fascinated by microscopes {#blank#}1{#/blank#} he'd built some of his own. One rainy day, as he went for a walk, a leaping frog {#blank#}2{#/blank#}(draw) his attention to a puddle.

    Antoni collected a drop of puddle water and put it{#blank#}3{#/blank#} his microscope. He was amazed{#blank#}4{#/blank#} (see) a whole community of creatures swimming in this one drop — tiny beings no one had ever seen before.

    These tiny beings, called microbes, are everywhere: in dirt, in food and on your kitchen table. People {#blank#}5{#/blank#} (cover) in them, too.{#blank#}6{#/blank#} you were to count all the microbes on and inside your body, you would find your body has more microbes than the world has people — over 6 billion!

    Microbes can't survive on {#blank#}7{#/blank#}(they) own. They need food. After {#blank#}8{#/blank#}(settle) into a home — you, for instance — they steal vitamins and other nutrients and leave behind dead cells and poisonous liquids called toxins. Some microbes can make you sick. People usually call these ones germs{#blank#}9{#/blank#} (lucky) for you, there are more {#blank#}10{#/blank#} (help) microbes, working together to keep you healthy, than bad ones.

    Cyclist Agustin Navarro was coming fourth in a race in Spain. But as he approached the finish line, he saw that his competitor Ismael Esteban had suffered a flat line and was running toward the finish line{#blank#}1{#/blank#} his bike over his shoulders. Agustin Navarro slowed down and refused{#blank#}2{#/blank#} (pass) him. Instead, he rode behind Ismael Esteban{#blank#}3{#/blank#} (allow) him to win the bronze medal.

    The people standing along the way applauded for Agustin Navarro's{#blank#}4{#/blank#} (behave) and cheered the two men as they made it toward the finish line —{#blank#}5{#/blank#} on foot; the other, on his bike. Mr. Esteban later tried to give{#blank#}6{#/blank#} prize to Agustin Navarro,{#blank#}7{#/blank#} he refused it.

    Agustin Navarro{#blank#}8{#/blank#} (praise) online for his unusual act since then. In a television interview, he told people that he didn't want to win like that, so he braked out of respect for somebody who had been{#blank#}9{#/blank#} (good) than himself. That's{#blank#}10{#/blank#} the spirit in a sport lies: respect competitors, teammates, coaches and even themselves.

    Yesterday I went shopping in the town. I was using my crutches(拐杖)on {#blank#}1{#/blank#} were two bags. I really struggled through the shopping mall. I was {#blank#}2{#/blank#}(tire)! After a while, I found a space and had {#blank#}3{#/blank#} rest there.

    Then I noticed Michael. He was my former student and he was a man {#blank#}4{#/blank#} his 40s. It's been years since I {#blank#}5{#/blank#}(teach) Michael, but he stopped to chat with me. When he noticed my crutches, he said, "Let me carry the bags for you." I thanked him but {#blank#}6{#/blank#}(polite) declined his offer. Then Michael pointed to a coffee shop nearby, "I will be here Rose Marie, if you change your mind." It was lovely and kind of {#blank#}7{#/blank#}(he) to give me an opportunity to change my mind.

    In fact, Michael is tattooed(纹身) on his arms. People think that guys like this are frightening, but there {#blank#}8{#/blank#}(be) nothing threatening about Michael. Michael's {#blank#}9{#/blank#}(appear) with tattoos is just his idea of sell-expression.

    {#blank#}10{#/blank#}(chat) with him helps me recognize the tenderness in the youth regardless of how they look.

    It was the spring of 1943 during World War Ⅱ. Standing among hundreds of new {#blank#}1{#/blank#}(soldier)at Camp Grant, Sam, just 18 years old, waited as a truck slowly drove by. {#blank#}2{#/blank#} full field pack was randomly thrown to each soldier.

    Sam received{#blank#}3{#/blank#} (he). After he opened the pack and looked at the things in it, he was greatly{#blank#}4{#/blank#}(astonish). He found his last name, Litrenti, was marked on each thing in his pack. "How strange!" Sam thought. He didn't think the one {#blank#}5{#/blank#} threw the field pack to him knew who he was.

    So why was Sam's last name marked on the things? You may not believe it, but it was the field pack that his father {#blank#}6{#/blank#}(use)during World War I.

    Sam {#blank#}7{#/blank#}(certain) didn't know that when he received it. It wasn't until after the war {#blank#}8{#/blank#} he found out why.

    After the war, he talked {#blank#}9{#/blank#}that with his father. After {#blank#}10{#/blank#} (talk)for a while, Sam's father became sure that the pack once belonged to him.

    Both the father and the son couldn't believe that! What a coincidence!

    The Beijing Vanke-Shijinglong Ski Resortis located{#blank#}1{#/blank#}Yanqing District, a national demonstration area for ecological construction. With Longqing Gorge to its east and Guanting Reservoir to its west, it has fresh air and an {#blank#}2{#/blank#}(impress) environment.{#blank#}3{#/blank#}(build) in 1999, it was the first large ski resort to be built near Beijing. In 2016, a massive renovation project {#blank#}4{#/blank#}(start) by Vanke, the Beijing Badaling Tourism General Company, and the original Beijing Shijinglong Ski Resort.

    The earth, the planet on {#blank#}1{#/blank#} we are living, is the third planet from the sun. It came from the shrinking (收缩) of a vast cloud of dust and gas in outer space. Many scientist believe that the earth, as well as the sun and the other planets in our solar system, {#blank#}2{#/blank#} (form) at least five billion years ago. The earth is slightly flattened at the North and South Poles, {#blank#}3{#/blank#} it would look like a perfect ball if you were far out in space.