Much of the world now lives in an industrial civilisation. But this has only become possible because we have the necessary natural resources. There are three types of natural resource without which industry could not exist. One of these is metal【Q31】 – without that we'd have no machines and no transportation. Another is fossil fuels, which we need to power those machines. But there's a third resource that's essential to connect the different parts of a machine together with belts and pipes and shock absorbers, and that is rubber. It's now used in over 40,000 products, from waterproof footwear to surgical gloves.
At present, we have two types of rubber in common use. One is natural rubber, which nearly all comes from the Pará rubber tree. This was originally native to Brazil, but is now cultivated on plantations in South-East Asia. Recently, however, concern's been growing that supplies may soon be insufficient for the world's needs. So what exactly is limiting the supply of natural rubber?
Well, for one thing, rubber trees don't just spring up overnight. It can take eight to ten years for a tree to start producing rubber, so cultivating them's a slow【Q32】 process. And this leads to another problem. With most crops, farmers don't have to think very far ahead, so they can easily change what crop they produce, or how much of a crop they produce, if they find the demand【Q33】 for that crop is rising or falling. But if you have to plant eight or ten years ahead, that's much harder. And also the rubber tree's very choosy about where it grows. It needs the right temperature, the right amount of rainfall, and the right altitude – not too high and not too low. The result is that it can't be grown in the northern or southern parts of the globe, only around the equator【Q34】. Another problem is that the rubber is basically extracted in the same way as it's been done for hundreds of years, and that's by hand, by making small cuts in the trunk of the tree, and putting a little cup there to catch the latex, as the rubber is called. It's very labour-intensive. And it's not just the initial production that's limiting supplies. With other resources such as water and glass, when we've finished using them we can recycle【Q35】 them, but although this is also possible with rubber, it's very difficult, so that also reduces the amount we have available.
And in the last few years, there have been new threats to the supply of natural rubber. One problem is linked to the fact that nearly all the rubber trees in South-East Asia are descended from just a small number of seeds brought from Brazil in the nineteenth century. This means that there's very little genetic diversity among the trees, which in turn makes them very vulnerable to disease. The most dangerous threat is a fungus 【Q36】, which destroyed large numbers of rubber trees in Brazil, and which could cause devastation to plantations worldwide. Another problem is that farmers in South-East Asia are increasingly turning to the cultivation of palm oil, which is easier and more profitable for them. And finally, in recent years South-East Asia, like other parts of the world, has been repeatedly hit by extreme types of weather【Q37】, and this looks likely to continue in the future.
However, as well as using natural rubber, it's also possible to make rubber synthetically. This works very well for some purposes, for example, making engine parts, or silicone pots and pans used for cooking. But compared with natural rubber, it's not anything like as strong【Q38】, and this means it can't replace natural rubber in other products. For example, while a mixture of natural rubber and synthetic rubber works well in car tyres, only natural rubber can stand up to the extreme speeds of aircraft tyres during take-off and landing.
So for some time, scientists have been looking for alternative sources of natural rubber. One that's been known about for some time seems initially to be a rather unlikely source. It's a wild plant with yellow flowers that we normally regard as a weed when we see it in our gardens. But when it's pulled up and its roots【Q39】 cut open, they're found to contain rubber.
Now, compared to the rubber tree, dandelions produce relatively small amounts of rubber, but unlike rubber trees, they're very adaptable. They'll grow in all sorts of places, and they don't need rich soil【Q40】. So at present there are several projects underway investigating the possibility of using dandelions as a source of rubber.
Another possibility is a desert shrub grown in Mexico and Texas ...
Complete the notes below.
Write ONE WORD ONLY for each answer.
听前预测：定位词 three resources、industrial civilisation，提示词 essential，此处应填名词。
题目解析：本题定位不难，题干信息 industrial civilisation 和 three resources 先后原词出现。 原文答案句为“There are three types of natural resource without which industry could not exist. One of these is metal—without that we'd have no machines and no transportation.”，意为“工业的存续离不开三类自然资源。金属便是其中之一；倘若没有金属，人类就不会拥有机器与交通运输体系。”题干列出“三大工业必 备资源： 、化石燃料、橡胶”，音频依次介绍三类资源，第一类对应原词 metal，直接填写。本题难度不大。
听前预测：定位词 growth of the tree，提示词 is，此处应填形容词。
题目解析：该题定位需要结合上一行信息“The supply is limited because”。听到原文提到“So what exactly is limiting the supply of natural rubber?”，意为“那么，究 竟是什么因素在制约天然橡胶的供应？”提示准备抓取。随即听到“Well, for one thing…”引出第一个限制供应的原因，听到这里，直接锁定出题句“It can take eight to ten years for a tree to start producing rubber, so cultivating them’s a slow process.”，意为“一棵树要历经 8—10 年才能开始产出橡胶，所以种植橡胶树是一个十分漫长的过程。”根据预判，刻意听段落里描述种树这件事的形容词—— 音频 cultivating them's a slow process 中听到形容词 slow 立刻记下来，不用纠结 growth 有没有读到。其中 cultivating them（种植培育橡胶树）替换题干信息 the growth of the tree（树木生长）。因此确认 slow 为该题正确答案，故填写。
听前预测：定位词 production，提示词 adjusted、increasing or decreasing，此处应填名词。
题目解析：上一题讲完树木生长慢，音频出现分层逻辑词 And this leads to another problem，标志进入该题出题区间，无须寻找题干原词即可锁定范围。原文答案句为“With most crops, farmers…can easily change what crop they produce, or how much of a crop they produce, if they find the demand for that crop is rising or falling.”，意为“对于大多数农作物而言，如果农民发现某种作物的市场需求上涨或者下降， 他们……可以很容易地调整种植的作物种类，或是调整该作物的种植规模。”题干含义为“产量难以根据增减的 进行调整”，原文说明农户会根据作物需求的涨跌调整种植量，橡胶树生长周期太长导致无法灵活调整，因果逻辑一 致。该句中的 rising or falling 对应题干信息 increasing or decreasing，因此 rising or falling 在句中修饰的名词 demand 完全匹配该题空格所需，故填写。
听前预测：提示词 near the，此处应填名词。
题目解析：依托递进连接词 And also，开启第三个限制橡胶供给的因素，直接划定本题出 题范围，不必纠结题干原词复现。原文答案句为“It needs the right temperature, the right amount of rainfall, and the right altitude…it can't be grown in the northern or southern parts of the globe, only around the equator.”，意为“它需要适宜的温度、合适的降雨量以及恰当的海拔……它无法在地球的北部或南部地区种植， 只能在赤道周边生长。”题干表达橡胶树只能生长在附近，原文讲明橡胶树无法在南北区域栽种，仅赤道地带可以种植，语义完全契合。其中题干介词结构 near the 和原文 around the 构成同义替换，后面衔接的名词 equator 即答案，故填写。
听前预测：提示词 difficult、to、after production，此处应填动词原形。
题目解析：借助过渡短语 Another problem，开启本条限制橡胶供应量的原因，快速锁定本题听音区间。原文答案句为“…when we've finished using them we can recycle them, but although this is also possible with rubber, it's very difficult…”，意为“……当我们用完这些材料后可以将它们回收利用，虽说橡胶同样能够回收，但回收难度极大……”题干句意为“橡胶产出之后很难进行 ”，原文表示橡胶制品完成使用后，回收工序难度很大，文意相互对应。题干信息 after production 对应原文 finished using them（橡胶制品完成生产投入使用之后）；题干结构“difficult to + 动词”对应原文 it's very difficult to recycle，因此动词原形 recycle 即答案，故填写。
听前预测：定位词 genetic diversity、disease，提示词 a，此处应填单数名词。
题目解析：通过音频过渡句“And in the last few years, there have been new threats to the supply of natural rubber.”，意为“而且在过去几年里，天然橡胶的供应又出现了一些新的威胁。”转入全新板块“橡胶产业面临的新型隐患”，判定进入该题答题范围。听到题干定位词 genetic diversity 和 disease 先后原词出现，准备抓取。答案句随后出现“The most dangerous threat is a fungus, which destroyed large numbers of rubber trees in Brazil, and which could cause devastation to plantations worldwide.”，意为“最危险的威胁来自一种真菌。它已经摧毁了巴西大量的橡胶树，并且有可能给全球的橡胶种植园带来毁灭性打击。”根据题干要求，需要填写导致橡胶树遭遇病害的因素，判断 fungus 符合搭配要求，故填写。
听前预测：提示词 extreme、events，此处应填名词。
题目解析：音频出现衔接词 And finally，引出最后一项威胁，直接锁定本题听音段落。原 文定位句 in recent years South-East Asia, like other parts of the world, has been repeatedly hit by extreme types of weather…，意为“近年来，东南亚和世界其他部分地区一样，频频遭受极端天气的侵袭……”题干 extreme 和音频原词完全重合，原文中的 extreme types of weather 精简为题干的“extreme events（极端天气事件）”，提取核心名词 weather，故填写。
听前预测：提示词 less，此处应填形容词。
题目解析：话题过渡至合成橡胶（synthetic rubber）板块，先听到上一行信息 engine/pots and pans used for cooking（cooking utensils），接着依靠转折连词 But 划分语义区间，锁定本题出题位置。原文答案句为“But compared with natural rubber, it's not anything like as strong, and this means it can't replace natural rubber in other products.”，意为“但和天然橡胶相比，它的强度远远不及，这就意味着它无法在其他产品上替代天然橡胶。”题干结构“less + 形容词”和原文 not…as strong 构成同义改写，表达合成橡胶强度比不上天然橡胶，因此形容词 strong 即答案，故填写。
听前预测：定位词 wild flower、dandelion，提示词 its，此处应填名词。
题目解析：文本切换至天然橡胶替代原料的话题，借助过渡引导句“So for some time, scientists have been looking for alternative sources of natural rubber.”划定本题听音范围。该句意为“因此，一段时间以来，科学家一直在寻找天然橡胶的替代来源。”听到题干信息 it's a wild plant with yellow flowers，意为“它是一种开黄花的野生植物”，准备抓取。答案句由转折词引出，“But when it's pulled up and its roots cut open, they're found to contain rubber.”意为“但把它拔起、切开根部后，就能发现根部含有橡胶。”题干介词结构“in its ”，对应音频 its roots cut open，这种野花的根部存有橡胶，直接提取原词 roots，故填写。
听前预测：提示词 many locations、not、good，此处应填名词。
题目解析：承接上一题蒲公英（dandelion）橡胶源的话题，本句继续阐述该作物的种植优势。答案句由转折词引出，“…but unlike rubber trees, they're very adaptable. They'll grow in all sorts of places, and they don't need rich soil.”意为“……但和橡胶树不同，它们的适应性很强，可以在各种各样的地方生长，而且不需要肥沃的土壤。”题干信息“does not require good ”对应音频内容“don't need rich soil”，其中 rich = good（肥沃的、优质的），核心名词 soil 为答案，完 全匹配空格搭配“ good + 名词”，故填写。
