Water hyacinth

文章大意

两名学生Alia和John讨论水葫芦的研究。水葫芦原产南美亚马逊流域，开紫蓝色花，被引入欧非作观赏植物后泛滥成灾，堵塞河道与水坝、影响发电和捕鱼、遮蔽水面抑制藻类并威胁鱼类生存，在营养丰富的水体中繁殖最快。

题目与答案

1. 21-22 Which TWO problems are caused by water hyacinth?
   • plants and fish are poisoned.
   • farmers cannot fish.
   • the dam`s structure is damaged.
   • electricity production is affected.

   答案：farmers cannot fish.,electricity production is affected.

   原文定位：Farmers cannot travel in boats on the water and thus cannot fish in it. In addition, heavy free‑floating mats of water hyacinth are clogging the dam at the power station in West Africa. Turbines of the power station are often shut down because of the intertwined leaves. Dams often cease to function as a result, severely restricting the electricity generation

   同义替换：「production」↔「generation」，「affected」↔「restricted」

2. 23 Where was water hyacinth originally from?
   • Latin America
   • Africa
   • Europe

   答案：Latin America

   原文定位：The water hyacinth is native to the Amazon basin in Latin America. It has spread mainly to the tropics and subtropics from much of the world since the eighteen hundreds. Later, it was introduced into Europe and Africa as an ornamental garden pond plant due to its beauty

   同义替换：「originally」↔「native」，「Latin America」↔「Latin America」

3. 24 What is the primary cause of the decrease in nutrients from the soil?
   • soil erosion
   • a change of rainfall
   • loss or trees

   答案：loss or trees

   原文定位：The main reason for soil nutrient loss is that local residents cut down trees

   同义替换：「primary cause」↔「main reason」，「decrease」↔「loss」，「loss of trees」↔「deforestation」

4. 25 When will the biological solution bring risks to the environment?
   • immediately
   • 6 months later
   • many years later

   答案：many years later

   原文定位：The side effects of this method on local ecology will remain unforeseen for years because it takes time for this external insect species to reach a density sufficient enough to affect ecological development

5. 26 What does John say about the mechanical solution?
   • ineffective
   • dangerous
   • expensive

   答案：expensive

   原文定位：Well, the mechanical removal of water hyacinth is seen as the best short-term solution. This option includes harvesting plants and inside cutting. This method can immediately open physical space for fish and boat traffic. It is, however, inefficient for workers to process extensive areas and costly to use large cutting and dredging equipment

   同义替换：「expensive」↔「costly」，「mechanical solution」↔「mechanical removal」

6. dried water hyacinth
   • can reduce the effect of global warming.
   • can be used an alternative energy resource.
   • can make quick profits.
   • can produce materials for plants to grow in.
   • can be good for human health.
   • can produce fertilizer.

   答案：can produce materials for plants to grow in.

   原文定位：water hyacinth is left to dry under the sun for a few days before being mixed with ash and animal manure. The mixture can be used as alternative soil rather than fertilizer. It can grow crops with increased yield

   同义替换：「dried」↔「left to dry under the sun」，「can produce materials for plants to grow in」↔「used as alternative soil」

7. mushroom farmers
   • can reduce the effect of global warming.
   • can be used an alternative energy resource.
   • can make quick profits.
   • can produce materials for plants to grow in.
   • can be good for human health.
   • can produce fertilizer.

   答案：can make quick profits.

   原文定位：Mushroom farmers can benefit from water hyacinth as well. Using the mixture mentioned earlier, mushrooms generally grow much faster so that farmers can harvest mushrooms sooner, which enables them to make money faster

   同义替换：「make quick profits」↔「make money faster」，「mushroom farmers」↔「Mushroom farmers」

8. oyster and straw mushrooms
   • can reduce the effect of global warming.
   • can be used an alternative energy resource.
   • can make quick profits.
   • can produce materials for plants to grow in.
   • can be good for human health.
   • can produce fertilizer.

   答案：can be good for human health.

   原文定位：Yes. In India, attempts have been made to grow these types of edible mushrooms organically utilizing water hyacinth. These mushrooms provide sufficient nutritional values, including minerals and high quality protein, which are essential to people's level of fitness

   同义替换：「good for human health」↔「nutritional values」，「mushrooms」↔「mushrooms」

9. cows
   • can reduce the effect of global warming.
   • can be used an alternative energy resource.
   • can make quick profits.
   • can produce materials for plants to grow in.
   • can be good for human health.
   • can produce fertilizer.

   答案：can be used an alternative energy resource.

   原文定位：In Southeast Asia, people feed cows using chopped water hyacinth mixed with other vegetables. Then the waste from the cows is treated to produce methane gas, which can be used as fuel for cooking, lighting, or powering an engine. And with global warming getting worse, developing alternative sources of energy will be more urgent than ever

   同义替换：「cows」↔「cows」，「alternative energy resource」↔「alternative sources of energy」