Once upon a time, a blind man was sitting at the roadside with a hat by his feet. There was a sign beside him, {#blank#}1{#/blank#} (say), “I am blind. Please help me.” {#blank#}2{#/blank#} good many passers-by walked by him, but few of them helped him.

    A creative young man named Tom was going to his office. While walking by the blind man, he stopped {#blank#}3{#/blank#}(see) that the man only had a few coins in his hat. He bent down and put a few of his own coins in the hat. Without asking for the blind man's {#blank#}4{#/blank#}(permit), he took the sign, turned it around and wrote a new message. Then he put the sign by the feet of the blind man, and left.

    {#blank#}5{#/blank#} (late) that afternoon, when Tom returned to the blind man, he saw the hat {#blank#}6{#/blank#}(fill) with bills and coins. The blind man recognized his footsteps and asked if {#blank#}7{#/blank#} was he who had changed his sign. He also wanted to know {#blank#}8{#/blank#} the man had done to the sign.

    Then the young man told the blind man that he {#blank#}9{#/blank#} (write) something like this on the sign, “It is spring now, but I can't see it.” {#blank#}10{#/blank#} （hear）what the young man said, the blind man expressed his gratitude to him and went home happily.

    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.

    Today, Mount Qomolangma's peak is not a lonely place any more. Over 3500 people have{#blank#}1{#/blank#} (successful) climbed the mountain over the past years. Meanwhile, climbers have complained about{#blank#}2{#/blank#}(wait) for hours in the bottlenecks.

    In fact, the dangerous{#blank#}3{#/blank#}(crowd) aren't the only problem. All those climbers need {#blank#}4{#/blank#}(bring) a lot of gear (装置) and much of them ends up being left on the mountains becoming the world's{#blank#}5{#/blank#} (tall) rubbish dump.

    But the good news is{#blank#}6{#/blank#} some mountaineers are overtaking it to clean up Qomolangma. Mountaineers Paul and Eberhard are part of Eco Everest Expedition which has been cleaning up rubbish since 2008.So far they{#blank#}7{#/blank#}(collect)over 13 tons of garbage.

    Some of that rubbish is even being used for{#blank#}8{#/blank#} higher purpose. As part of the Mount Everest 8844 Art Project, a group of 15 artists Nepal collected 1.5 tons of garbage. They've changed the cans and oxygen tanks into74 piece of art that have are exhibited{#blank#}9{#/blank#}Nepal's capital. Part of the profit from sales{#blank#}10{#/blank#} (be) available for the Everest Pakeers Association which has helped ole rubbish of the mountain.