英语听力文摘 English Digest 205、喜欢毒素的树

　　Toxin¹-loving Trees
树木能调节气候,保持生态平衡，树木通过光合作用，吸进二氧化碳,吐出氧气,使空气清洁，新鲜。一亩树林放出的氧气够65人呼吸一辈子。树还能防风固沙，涵养水土,吸收各种粉尘，一亩树林一年可吸收各种粉尘20－60吨.。树林也能够减少噪音污染，40米宽的林带可减弱噪音10－15分贝。噪音的污染对人类的生活、学习、工作、休息等方面都造成了很大的危害，可以说是人们的“敌人”。因此我们更要重视植树造林。树木的分泌物能杀死细菌。空地每立方米空气中有3，4万个细菌，森林里只有300-400个。植树造林是我们每个公民的义务，国家还专门规定了在三月十二日这天为植树节。植树造林对我们的学习、工作、生活等方面都有很大的好处。树可以减低温度，和提高湿度30度气温可以降到二十几度左右。

　　In our increasingly complex age of high technology and instant electronic communication, it’s important to recall a few simple truths. Forexample–trees are good. Think about it trees help hold soil in place, create oxygen, and provide shade on hot summer days. And now, thanks to researchers at the University of Georgia, trees may soon help us clean up toxic² waste.
Here’s how it works. Scientists isolated³ a gene⁴ from a type of bacteria that thrives in places polluted by mercury–a metal that is highly toxic in large amounts.
They then implanted the gene, which converts mercury into a less-toxic form, into day-old saplings. Once the genetically⁵ engineered trees were big enough, they were transplanted to soil contaminated by mercury.  When tested against regular trees, the genetically enhanced trees were able to absorb and dilute⁶ ten times more mercury, which they released into the air as harmless vapor⁷. In fact, the trees seemed to thrive on mercury. When grown in soil lacking the toxin, the trees became weak and sickly.
Mercury pollution is a serious threat to wildlife and to humans. Eating fish that have ingested large amounts of mercury, for example, can cause neurological damage in humans. Cleaning up soil and water polluted by mercury is typically very expensive, which makes mercury absorbing trees an even more attractive prospect⁸. Trees are relatively⁹ cheap to grow and plant, and scientists hope to engineer trees to absorb other toxins¹⁰ besides mercury.
It remains¹¹ to be seen how well the trees will function on a wider scale. But if they are able to help decontaminate our soil and water, we’ll have even more reason to appreciate toxin-loving trees.

1 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

2 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

3 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

4 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

5 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

6 dilute   

vt.稀释，冲淡；adj.稀释的，冲淡的

参考例句：

• The water will dilute the wine.水能使酒变淡。
• Zinc displaces the hydrogen of dilute acids.锌置换了稀酸中的氢。

7 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

8 prospect   

n.前景，前途；景色，视野

参考例句：

• This state of things holds out a cheerful prospect.事态呈现出可喜的前景。
• The prospect became more evident.前景变得更加明朗了。

9 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

10 toxins   

n.毒素( toxin的名词复数 )

参考例句：

• The seas have been used as a receptacle for a range of industrial toxins. 海洋成了各种有毒工业废料的大容器。
• Most toxins are naturally excreted from the body. 大部分毒素被自然排出体外。 来自《简明英汉词典》

11 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。