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        主題語(yǔ)境十四:自然(二)

        2020-02-20 14:30
        關(guān)鍵詞:基本知識(shí)連貫詞數(shù)

        I. 閱讀理解

        When a leafy plant is under attack, it doesn't sit quietly. Back in 1983, two scientists, Jack Schultz and Ian Baldwin, reported that young maple trees getting bitten by insects send out a particular smell that neighboring plants can get. These chemicals come from the injured parts of the plant and seem to be an alarm. What the plants pump through the air is a mixture of chemicals known as volatile organic compounds, VOCs for short.

        Scientists have found that all kinds of plants give out VOCs when being attacked. It's a plant's way of crying out. But is anyone listening? Apparently. Because we can watch the neighbors react.

        Some plants pump out smelly chemicals to keep insects away. But others do double duty. They pump out perfumes designed to attract different insects who are natural enemies to the attackers. Once they arrive, the tables are turned. The attacker who was lunching now becomes lunch.

        In study after study, it appears that these chemical conversations help the neighbors. The damage is usually more serious on the first plant, but the neighbors, relatively speaking, stay safer because they heard the alarm and knew what to do.

        Does this mean that plants talk to each other? Scientists don't know. Maybe the first plant just made a cry of pain or was sending a message to its own branches, and so, in effect, was talking to itself. Perhaps the neighbors just happened to “overhear” the cry. So information was exchanged, but it wasn't a true, intentional back and forth.

        Charles Darwin, over 150 years ago, imagined a world far busier, noisier and more intimate (親密的) than the world we can see and hear. Our senses are weak. There's a whole lot going on.

        1. What does a plant do when it is under attack?

        A. It makes noises. B. It gets help from other plants.

        C. It stands quietly. D. It sends out certain chemicals.

        2. What does the author mean by “the tables are turned” in paragraph 3?

        A. The attackers get attacked.

        B. The insects gather under the table.

        C. The plants get ready to fight back.

        D. The perfumes attract natural enemies.

        3. Scientists find from their studies that plants can _______.

        A. predict natural disasters B. protect themselves against insects

        C. talk to one another intentionally D. help their neighbors when necessary

        4. What can we infer from the last paragraph?

        A. The world is changing faster than ever. B. People have stronger senses than before.

        C. The world is more complex than it seems. D. People in Darwin's time were more imaginative.

        Ⅱ. 完形填空

        The small town of Rjukan in Norway is situated between several mountains and does not get direct sunlight from late September to mid-March— 1six months out of the year.

        “Of course, we2it when the sun is shining,” says Karin Ro, who works for the town's tourism office. “We see the sky is3 , but down in the valley it's darker—it's like on a4day.”

        But that5when a system of high-tech6was introduced to reflect sunlight from neighboring peaks (山峰) into the valley below. Wednesday, residents (居民) of Rjukan7their very first ray of winter sunshine: A row of reflective boards on a nearby mountainside were put to8 . The mirrors are controlled by a computer that9them to turn along with the sun throughout the

        10and to close during windy weather. They reflect a concentrated beam (束) of light onto the town's central11 , creating an area of sunlight roughly 600 square meters. When the light12 , Rjukan residents gathered together.

        “People have been13there and standing there and taking14of each other,” Ro says. “The town square was totally15 . I think almost all the people in the town were there.” The 3,500 residents cannot all16the sunshine at the same time.17 , the new light feels like more than enough for the town's18residents.

        “It's not very19 ,” she says, “but it is enough when we are20 .”

        III. 語(yǔ)法填空

        When man starts his work in nature, the balance is likely 1. ____________ (destroy). He grows a crop and takes it away to eat; then there are no dead leaves to fall on the ground, holding water while it sinks into the surface. 2. ____________ a farmer acts with knowledge and skill, he is therefore most likely to make the land 3. ____________(bad) year by year. 4. ____________(take) the place of the useful matter in the crops that he removes, he uses some kind of fertilizer. In some places, it is a habit to burn waste material lying about, but such burning destroys the useful matter

        5. ____________the plants need to grow. Although the ashes that are left are valuable when put on the land, a better practice is to bury the waste so that it decays and increases the humus(腐殖質(zhì)) in the soil.

        In the past, when the world population was much less than it is now, a man had little difficulty 6. ____________(grow) the food that was needed. When a field had been used for some years and had become tired, the farmer could move to another place. The tired land then slowly recovered. Gradually grasses and other plants would appear on it and its 7. ____________(produce) power would slowly return to normal through their decay. But nature, 8. ____________(leave) alone, would take a long time to bring back the land to its former state; the 9. ____________(long) of time required would depend on local conditions, but it might well be ten years.

        Anyway, it is a bad practice to grow the same crop in a field year after year and is man's responsibilities to find solutions 10. ____________ the problem of soil protection.

        IV. 書面表達(dá)

        請(qǐng)根據(jù)下面的提示寫一篇短文,介紹颶風(fēng)(hurricane)的一些基本知識(shí)。

        注意:

        1. 詞數(shù)100左右;

        2. 可以適當(dāng)增加細(xì)節(jié),以使行文連貫。

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