Dirty River but Clean Water

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题目与答案

1. 1 Damage caused by a fire is worse than that caused by the flood.
   • TRUE
   • FALSE
   • NOT GIVEN

   答案：NOT GIVEN

   原文定位：Fire and flood are two of humanity’s worst nightmares

2. Humpback chub population reduced, why?

   Then several species disappeared including Colorado pike-minnow, 10_____ and the round-tail chub.

   答案：razorback sucker

   原文定位：These include the Colorado pike-minnow, the razorback sucker and the roundtail chub

3. Meanwhile, some moved in such as fathead minnows, channel catfish and 11_____.

   答案：common carp

   原文定位：aliens including fathead minnows, channel catfish and common carp, which would have been hard, put to survive in the savage waters of the undammed canyon, have moved in

4. The non-stopped flow led to the washing away of the sediment out of the canyon, which poses a great threat to the chubs because it has poor 12_____ away from predators.

   答案：visibility

   原文定位：The chub were well adapted to the poor visibility created by the chick, red water which gave the river its name and depended on it to hide from predators. Without the cloudy water, the chub became vulnerable

   同义替换：「non-stopped flow washed sediment away」↔「without the cloudy water」

5. In addition, the volume of 13_____ available behind the dam was too low to rebuild the bars and flooding became more serious.

   答案：sand

   原文定位：on that occasion, the volume of sand available behind the dam was too low to rebuild the sandbanks

   同义替换：「bars」↔「sandbanks」

6. 2 The flood peaks at almost 1500 cubic meters every eight years.
   • TRUE
   • FALSE
   • NOT GIVEN

   答案：FALSE

   原文定位：Spring Snow from as far away as Wyoming would melt and swell the Colorado river to a flow that averaged around 1,500 cubic metres (50,000 cubic feet) a second. Every eight years or so, that figure rose to almost 3,000 cubic metres

   同义替换：「peaks」↔「rose」

7. 3 Contribution of sediments delivered by tributaries has little impact.
   • TRUE
   • FALSE
   • NOT GIVEN

   答案：NOT GIVEN

   原文定位：Even that has not been much use as those tributaries are not powerful enough to distribute the sediment in an ecologically valuable way

   同义替换：「little impact」↔「not been much use」，「contribution」↔「impact」

8. 4 The decreasing number of chubs is always caused by introducing of trout since the mid 20th century.
   • TRUE
   • FALSE
   • NOT GIVEN

   答案：FALSE

   原文定位：At first sight, it looked as if the reason was that the chub were being eaten by trout;But trout and chub co-existed until the Glen Canyon dam was built, so something else is going on

9. 5 It seemed that the artificial flood in 1996 had achieved success partly at the very beginning.
   • TRUE
   • FALSE
   • NOT GIVEN

   答案：TRUE

   原文定位：In 1996 the flood was allowed to go on too long. To start with, all seemed well

   同义替换：「at the very beginning」↔「To start with」

10. 6 In fact, the yield of artificial flood water is smaller than an average natural flood at present.
    • TRUE
    • FALSE
    • NOT GIVEN

    答案：TRUE

    原文定位：At less than 1,200 cubic metres a second, this flood is smaller than even an average spring flood

11. 7 Mighty floods drove fast-moving flows with clean and high-quality water.
    • TRUE
    • FALSE
    • NOT GIVEN

    答案：NOT GIVEN

12. The Eco-Impact of the Canyon Dam

    Floods are people’s nightmare. In the past, the canyon was raged by flood every year. The snow from far Wyoming would melt in the season of 8_____.

    答案：spring

    原文定位：Spring Snow from as far away as Wyoming would melt and swell the Colorado river

13. And caused a flood flow peak in Colorado river. In the four decades after people built the Glen Canyon Dam, it only could gather 9_____ together from tiny, undammed tributaries.

    答案：sediment

    原文定位：the only sediment that it has collected has come from tiny, undammed tributaries

    同义替换：「gather」↔「collected」