Each year {#blank#}1{#/blank#}(thousand) of tourists visit the polar regions of the Arctic and Antarctica. But the increasing number of people traveling to the ends of the Earth can have {#blank#}2{#/blank#}negative effect on fragile ecosystems. Should tourists {#blank#}3{#/blank#}(allow) to visit polar regions?

    About 40,000 tourists visit Antarctica each year. More than five million travel to the Arctic and sub-Arctic. Transporting tourists to the regions {#blank#}4{#/blank#}(increase) ship and airplane traffic, adding to the risk of pollution, oil spills, and other {#blank#}5{#/blank#}(environment) damage. Because the places where wildlife is accessible {#blank#}6{#/blank#}(be) few in number, tourist traffic can become concentrated in specific areas, {#blank#}7{#/blank#} (put)Arctic vegetation at risk.

    Others say that access {#blank#}8{#/blank#}these very special parts of the world should not be restricted to only researchers and scientists. Polar tourism allows people to develop deep  {#blank#}9{#/blank#}（person） connections with polar regions. “Those {#blank#}10{#/blank#}travel to the Arctic or Antarctica often become cheerleaders for supporting those places.” Jim Sano, vice president for travel and conservation at World Wildlife Fund, told TFK.

    You might want to think twice before purchasing{#blank#}1{#/blank#}(conventional) grown strawberries or spinach(菠菜). According to a new report from the Environmental Working Group(EWG), these foods are the most likely{#blank#}2{#/blank#}(pollute) with the pesticide.

    Even low levels of pesticide exposure can be harmful to infants, babies and young children,{#blank#}3{#/blank#}parents and caregivers should take measures to lower children's exposures{#blank#}4{#/blank#}pesticides while still{#blank#}5{#/blank#}(feed) them diets rich in healthy fruits and vegetables.

    Just last year, the red berry knocked apples and{#blank#}6{#/blank#}(hold) the title of the most polluted. The pesticide increased in strawberries because of out-of-season demand. The most polluted strawberry had traces of 20{#blank#}7{#/blank#}(vary) pesticides.

    Also moving up on{#blank#}8{#/blank#}list this year is spinach. Spinach jumps from the{#blank#}9{#/blank#}(eight) to the second most polluted product. The study finds spinach samples contain more pesticides by weight than all other produce{#blank#}10{#/blank#}(test). In high doses, it can cause damage to the nervous system.

—No, I'm just a bit tired.

    Ski touring is exactly that—touring on skis. It combines {#blank#}1{#/blank#} best bits of skiing and mountaineering and provides the perfect way {#blank#}2{#/blank#} (explore) the mountain in winter. The {#blank#}3{#/blank#} (advantage) of ski touring are that you can really escape the crowds, enjoy the peace of the mountains and {#blank#}4{#/blank#} (reward) with breathtaking views and exciting descents.

    Ski touring involves both going up and down the mountain; both of {#blank#}5{#/blank#} (they) present challenges and new skills are to be acquired. There is much to learn about getting up the mountain that improves efficiency and saves energy. {#blank#}6{#/blank#} (similar) ，you want to be prepared to enjoy going down, which means learning to deal with the variety of snow conditions you will face. Because all ski touring is very demanding, you must be {#blank#}7{#/blank#} good physical condition. The fitter you are, the {#blank#}8{#/blank#} (much) fun you will have.

    Rapidly changing conditions and the human factors are the primary reasons for accidents. The human factors include stress, poor {#blank#}9{#/blank#} (communicate), over-confidence and tiredness. You should always ski within the limits of your ability, and make sure you know {#blank#}10{#/blank#} to navigate (导航) properly with map and compass.

    Once there lived a rich man {#blank#}1{#/blank#} wanted to do something for the people of his town. {#blank#}2{#/blank#} first he wanted to find out whether they deserved his help.

    In the centre of the main road into the town, he placed {#blank#}3{#/blank#} very large stone. Then he {#blank#}4{#/blank#}(hide) behind a tree and waited. Soon an old man came along with his cow.

    “Who put this stone in the centre of the road?” said the old man, but he did not try to remove the stone. Instead, with some difficulty he passed around the stone and continued on his way. {#blank#}5{#/blank#} man came along and did the same thing; then another came ,and another. All of them complained about the stone but not tried to remove it. Late in the afternoon a young man came along. He saw the stone, {#blank#}6{#/blank#}(say) to himself: “The night {#blank#}7{#/blank#}(be) very dark. Some neighbors will come along{#blank#}8{#/blank#}(late) in the dark and will fall against the stone.”

    Then he began {#blank#}9{#/blank#}(move) the stone. He pushed and pulled with all his {#blank#}10{#/blank#} (strong) to move it. How great was his surprise at last! Under the stone, he found a bag of money.

    The Great Wall was listed as a World Heritage by UNESCO in 1987. Just like a dragon, it winds up and down across deserts, grasslands and mountains, {#blank#}1{#/blank#} (run) approximately 21, 196 kilometers from east to west.

    The {#blank#}2{#/blank#} (construct) of the Great Wall was not that easy, {#blank#}3{#/blank#} drew heavily on the local resources for building materials. The walls were {#blank#}4{#/blank#} (origin) built in the Spring & Autumn Period and the Warring States Period. Emperor Qin Shi Huang succeeded in his effort to have them joined together. Since then, the Great Wall {#blank#}5{#/blank#} (serve) as a monument of the Chinese nation throughout history.

    With {#blank#}6{#/blank#} history of about 2, 700 years, some parts of the Great Wall are now {#blank#}7{#/blank#} ruins or have disappeared. However, the Great Wall of China is still one of the most appealing {#blank#}8{#/blank#} (attraction) all around the world owing to its historical significance. The best-known part of the Great Wall of China, Badaling, {#blank#}9{#/blank#} (locate) 43 miles northwest of Beijing, attracts thousands of national and foreign tourists every day.

    Today, the Great Wall {#blank#}10{#/blank#} (recognize) as one of the most important impressive architectural achievements in history.