英语听力—环球英语 655 Fighting Japanese Knotweed

 

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　　Voice 1
Welcome to Spotlight¹. I'm Liz Waid.
Voice 2
And I'm Bruce Gulland. Spotlight uses a special English method of broadcasting. It is easier for people to understand, no matter where in the world they live.
Voice 1
Matthew and Susan were to be married. They were buying a new house near London, England. Matthew and Susan looked forward to their new life together in their new home. But a few months later their beautiful home was ruined. Not by earthquake, wind, or fire. It was ruined by a plant! The plant appeared next to the house soon after Matthew and Susan moved in, but in the coming months the plant began to grow through the floors of their house. Their house is now worth only twenty five percent of the price they paid for it. It may even have to be pulled down to enable² experts to kill the plant. The plant is 'Japanese Knotweed'.
Voice 2
Japanese Knotweed is a very strong plant. It is so powerful³ it can push its way up through roads and buildings. It damages walls and breaks through flood barriers⁴. Japanese Knotweed is causing a lot of damage in America, in Canada and in several European countries.
Voice 1
Japanese Knotweed comes from Japan - but it does not cause problems there because natural enemies keep it under control. In fact it is a useful plant in Japan. People who keep bees value it because these insects feed on it when many other plants are not in flower. And, in the spring, people eat the young stems⁵ of Japanese Knotweed as a vegetable. The plant is also used to produce several different kinds of medicines.
Voice 2
In the nineteenth century, plant lovers⁶ visited Japan from other countries. They discovered Japanese Knotweed, and they liked it. It was a big, beautiful plant that they thought would look good in their own countries. So, they collected seeds from the plants and took them back to their gardens. But they did not understand the dangers of taking plants and animals from one country to another country. In the case of Japanese Knotweed, these travellers⁷ made a big mistake.
Voice 1
Japanese Knotweed can grow a metre in one month. Its roots go down three metres into the ground and spread to seven metres wide. As it grows, it covers other plants and kills them. Japanese Knotweed can grow in any kind of soil. It does not matter how dry or how wet the soil is. It even grows in rivers - blocking the flow of water and causing floods.
Voice 2
Attempts to destroy this problem plant cost well over 200 million dollars every year in the UK alone. If you cut it down it grows again even more strongly. If you dig⁸ it up you must remove every single small piece of root from the ground. If you leave even one piece of root just one centimetre long it will grow again.
Voice 1
The best method of control has been to combine several different processes. The first step is to treat the plant with strong chemicals – weedkillers. This kills the parts of the plant above ground. The dead parts of the plants must be burned. Then even the soil the plant grew in must be treated, in order to destroy every piece of root. It usually takes up to three years before the plants are completely⁹ destroyed.
Voice 2
A new Olympic Stadium¹⁰ is being built in London, England. It will be ready for the Olympic Games in 2012. In 2004, Japanese Knotweed was discovered in the area where the Stadium was to be built. The plant was only in a very small part of the area but the situation was very serious. The building work could not begin until the Japanese Knotweed had been completely destroyed. It took a specialist¹¹ company two years to clear this small area of this problem plant.
Voice 1
British scientists have been experimenting to find a better way to control Japanese Knotweed. They wanted to discover a new method that is faster and less costly¹². A group of scientists visited Japan to study the plant in its natural environment. They discovered that, in Japan, the plant has two hundred natural enemies.
Most of these enemies are insects that eat the plant, or diseases¹³ that attack it. However most of these enemies also attack other plants. The scientists identified only two enemies that could be useful in controlling Japanese Knotweed in other countries.
Voice 2
One of these enemies is a very small insect called a Psyllid. This insect feeds only on Japanese Knotweed. The Psyllids do not kill all the plants but they do weaken¹⁴ them. The Psyllids keep Japanese Knotweed under control in Japan - and it does not cause damage to buildings and roads.
The scientists have studied this insect very carefully. They have tested it on ninety different plants in the UK. The Psyllid does not seem to eat any of them.
The UK government has given permission for tests to begin in three secret places in the UK. The scientists will take very great care to make sure the Psyllids do not escape and spread to other areas. Other countries in Europe are watching the experiments with great interest.
Voice 1
It is the first time that any European country has used bio-control. Bio-control uses a natural enemy to control a problem plant or animal. But such experiments have been tried in many other countries around the world. Some of these experiments have gone badly wrong.
Voice 2
One example is the cane¹⁵ toads¹⁷ that were brought to Australia in nineteen thirty five. Particular insects attack sugar cane when it is growing. The cane toad¹⁶ is an animal that loves to eat these insects. The problem is that the cane toad also likes to eat almost anything else! Even worse, the cane toad is poisonous. Animals that eat cane toads die. Australia now has a big problem - too many cane toads.
Voice 1
However, the scientists in the UK believe the Psyllids are completely safe because they do not eat anything other than Japanese Knotweed. Many people agree with them. These people think the Psyllids should be brought to the UK as soon as possible.
Voice 2
Other people are very worried about the idea. These people think that the Psyllids will change their behaviour when they arrive in the UK. They think that when the Japanese Knotweed has been destroyed the Psyllids will be forced to find something else to eat. They may then damage other plants.
Voice 1
The scientists who support the experiment say that Japanese Knotweed will never be destroyed completely. They believe the insects will just keep it under control. They believe the Psyllids will not need to eat anything else.
If that is the case, Japanese Knotweed could cease¹⁸ to be a problem in the UK. It could even become as useful as it is in Japan!
 

1 spotlight   

n.公众注意的中心，聚光灯，探照灯，视听，注意，醒目

参考例句：

• This week the spotlight is on the world of fashion.本周引人瞩目的是时装界。
• The spotlight followed her round the stage.聚光灯的光圈随着她在舞台上转。

2 enable   

vt.使能够；使可以；使成为可能

参考例句：

• Only teamwork will enable us to get the job done on time.只有团结一致，我们才能按时完成这项工作。
• This will enable China to go a step further in grain production.这是中国粮食生产再上新台阶的巨大动力。

3 powerful   

adj.有力的，有权力的，强大的

参考例句：

• The UN began to get more and more powerful.联合国开始变得越来越强大了。
• Such are the most powerful voices of our times!这些就是我们时代的最有力的声音！

4 barriers   

n.障碍( barrier的名词复数 )；屏障；栅栏；分界线

参考例句：

• The crowd had to stand behind barriers. 人群只好站在障碍物后面。
• the dissolution of barriers of class and race 阶级和种族隔阂的消除

5 stems   

n.（花草的）茎( stem的名词复数 )；词干；（高脚酒杯的）脚；烟斗柄v.遏制[阻止]（液体的流动等）( stem的第三人称单数 )；封堵；遏止

参考例句：

• The present wave of strikes stems from discontent among the lower-paid. 当前的罢工浪潮起因于低工资雇员们的不满情绪。 来自《简明英汉词典》
• Her interest in flowers stems from her childhood in the country. 她对花卉的兴趣产生于她在乡下度过的童年时代。 来自《简明英汉词典》

6 lovers   

爱好者( lover的名词复数 )； 情人； 情夫； 情侣

参考例句：

• They were off-screen lovers. 他们是真实生活中的情侣。
• Shakespeare's star-crossed lovers, Romeo and Juliet 罗密欧和朱丽叶这一对莎士比亚笔下命运多舛的恋人

7 travellers   

n.旅行者( traveller的名词复数 )；旅游者；旅客；游客

参考例句：

• The unusually heavy rainfall was an ill omen for the travellers. 异乎寻常的大雨是旅行者的不祥之兆。 来自《简明英汉词典》
• The travellers looked weather-beaten, there was little spit and polish. 旅客们满面风尘，仪容不整。 来自《简明英汉词典》

8 dig   

v.挖（洞，沟等）；掘

参考例句：

• It is difficult to dig the ground when it is frozen.地面冻住了就不易挖掘。
• In those days we often went to dig for wild vegetables.那时候我们常常出去挖野菜。

9 completely   

adv.完全地，十分地，全然

参考例句：

• She never completely gave up hope.她从不完全放弃希望。
• I feel completely in the dark on this question.这件事使我感到茫然。

10 stadium   

n.露天大型运动场

参考例句：

• The new football stadium can hold eighty thousand people.新的足球场可以容纳八万人。
• The stadium is being used for a match.那个露天运动场正在进行一场比赛。

11 specialist   

n.（医学）专家，专科医生；专家；专业人员

参考例句：

• She is a specialist in English.她是一位英语专家。
• The peasants looked up to him as a specialist.农民们尊他为专家。

12 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

13 diseases   

n.疾病( disease的名词复数 )；弊端；恶疾；痼疾

参考例句：

• Smoking is a causative factor in several major diseases. 抽烟是引起几种严重疾病的病因。
• The illness frequently coexists with other chronic diseases. 这种病往往与其他慢性病同时存在。

14 weaken   

v.(使)变弱，(使)虚弱

参考例句：

• You can weaken the tea by adding water.你可以加水把茶弄得淡一些。
• We never weaken our efforts in face of difficulties.我们在困难面前从不软化我们的努力。

15 cane   

n.手杖，细长的茎，藤条；v.以杖击，以藤编制的

参考例句：

• This sugar cane is quite a sweet and juicy.这甘蔗既甜又多汁。
• English schoolmasters used to cane the boys as a punishment.英国小学老师过去常用教鞭打男学生作为惩罚。

16 toad   

n.蟾蜍，癞蛤蟆

参考例句：

• Both the toad and frog are amphibian.蟾蜍和青蛙都是两栖动物。
• Many kinds of toad hibernate in winter.许多种蟾蜍在冬天都会冬眠。

17 toads   

n.蟾蜍，癞蛤蟆( toad的名词复数 )

参考例句：

• All toads blink when they swallow. 所有的癞蛤蟆吞食东西时都会眨眼皮。 来自《简明英汉词典》
• Toads have shorter legs and are generally more clumsy than frogs. 蟾蜍比青蛙脚短，一般说来没有青蛙灵活。 来自辞典例句

18 cease   

n.停止，终止；v.停止

参考例句：

• The two parties made a bargain to cease fire.双方达成了停火协议。
• You will never cease to learn as long as you live.活到老，学到老。