For my project on invertebrates, I chose to study tardigrades. These are microscopic- or to be more precise - near-microscopic animals. There are well over a thousand known species of these tiny animals, which belong to the phylum Tardigrada . Most tardigrades range in length from 0.05 to 1 millimetre, though the largest species can grow to be 1.2 millimetres in length. They are also sometimes called 'water bears': 'water' because that's where they thrive best, and 'bear' because of the way they move. 'Moss piglet' is another name for tardigrades because of the way they look when viewed from the front. They were first discovered in Germany in 1773 by Johann Goeze, who coined the name Tardigrada. As I say, there are many different species of tardigrade - too many to describe here - but, generally speaking, the different species share similar physical traits. They have a body which is short, and also rounded - a bit like a barrel - and the body comprises four segments. Each segment has a pair of legs, at the end of which are between four and eight sharp claws. I should also say that some species don't have any claws; what they have are discs, and these work by means of suction. They enable the tardigrade to cling on to surfaces or to grip its prey. Within the body, there are no lungs, or any organs for breathing at all. Instead, oxygen and also blood are transported in a fluid that fills the cavity of the body. As far as the tardigrade's head is concerned, the best way I can describe this is that it looks rather strange - a bit squashed even - though many of the websites I looked at described its appearance as cute, which isn't exactly very scientific. The tardigrade's mouth is a kind of tube that can open outwards lo reveal teeth-like structures known as 'slylets'. These are sharp enough to pierce plant or animal cells. So, where are lardigrades found? Well,they live in every part of the world, in a variety of habitats: most commonly, on the bed of a lake, or on many kinds of plants or in very wet environments. There's been some interesting research which has found that tardigrades are capable of surviving radiation and very high pressure, and they're also able to withstand temperatures as cold as -200 degrees centigrade, or highs of more than 148 degrees centigrade, which is incredibly hot. It has been said that tardigrades could survive long after human beings have been wiped out, even in the event of an asteroid hitting the earth. If conditions become too extreme and tardigrades are at risk of drying out, they enter a state called cryptobiosis. They curl into a ball, called a tun - that's T-U-N - by retracting their head and legs, and their metabolism drops to less than one percent of normal levels. They can remain like this until they are re-introduced to water, when they will come back to life in a matter of a few hours. While in a state of cryptobiosis, tardigrades produce a protein that protects their DNA. In 2016, scientists revived two tardigrades that had been tuns for more than 30 years. There was a report that, in 1948, a 120-year-old tun was revived, but this experiment has never been repeated. There are currently several tests taking place in space. to determine how long tardigrades might be able to survive there. I believe the record so far is 10 days. So, erm, moving on. In terms of their diet, tardigrades consume liquids in order to survive. Although they have teeth, they don't use these for chewing. They suck the juices from moss, or extract fluid from seaweed, but some species prey on other tardigrades, from other species or within their own. I suppose this isn't surprising, given that tardigrades are mainly comprised of liquid and are coated with a type of gel. Finally, I'd like to mention the conservation status of tardigrades. It is estimated that they have been in existence for approximately half a billion years and, in that time, they have survived five mass extinctions. So, it will probably come as no surprise to you, that tardigrades have not been evaluated by the International Union for Conservation of Nature and are not on any endangered list. Some researchers have described them as thriving. Does anyone have any questions they'd like to ask?
Complete the notes below.
Write ONE WORD ONLY for each answer.
听前预测： 定位词为 water ‘bears’、moss piglets；提示词为 due to how they，此处应填动词，内容应为水熊虫（water ‘bears’）的动作。
题目解析： 本题定位词 water ‘bears’ 先出现，注意听动词。原文先解释‘water’ because that’s where they thrive best, and ‘bear’ because of the way they move，意为“称其为‘水’是因为这是它们在水中可以快速繁殖，而称其为‘熊’则是因为它们的移动方式”，其中，thrive 虽然也是动词，但是不能与题干中 how they 的表述搭配，此处强调的是 where。而原文中的 move 一词则与题干信息搭配，题干中的how 一词，在原文中被替换为 the way，故填写。考生应注意迭代的做题策略，以及答案信息和题干的语法、语义适配性。听到答案后原文马上出现另一定位词 moss piglets，故可进一步确认答案。
听前预测： 定位词为 round body、legs；提示词为 Physical appearance、a，此处应填辅音开头的名词或形容词，内容应为对水熊虫体型的描述。
题目解析： 本题定位词 body 原词出现，随后马上听到关于体型的描述 They have a body which is short, and also rounded，意为“他们的身体又短又圆”，short 符合预判方向，且后续提及的 rounded 一词进一步确认其为答案，故填写。
听前预测： 定位词为 claws；提示词为 or，此处应填名词，内容应为对于水熊虫体貌特征的描述，且与 claws 一词存在选择关系。
题目解析： 本题定位词 claws 先原词出现，注意这时不要着急。在雅思听力命题中，并列、选择关系结构中答案前项的词往往在原文中会展开描述，因此听到出现 claws的后一个词，不一定就是答案信息。此时，先听到 I should also say that somespecies don’t have any claws，意为“应该说还有些水熊虫没有爪子”，该句子出现否定信息，不符合题干态度方向，因此不可能是答案，继续听。听到评价what they have are discs, and these work by means of suction，意为“它们拥有的是起吸附作用的圆盘”，其中 discs 符合题干用词搭配和逻辑结构，故填写。
听前预测： 定位词为上一句中的 respiratory organs 以及本句中的 liquid、blood；提示词为carries both、and，此处应填名词，内容应该为水熊虫体液中携带的物质。
题目解析： 本题定位词 organs 先原词出现，但较难的 respiratory（呼吸的）一词被替换为具体的描述 Within the body, there are no lungs, or any organs for breathing at all，意为“它们体内没有肺，也没有任何呼吸器官”，此处对应前文和本题的衔接性信息 absence of respiratory organs。此时要做好开始听本题的准备，随后马上听到Instead, oxygen and also blood are transported in a fluid that fills the cavity of the body，意为“相反，氧气和血液由充满身体空腔的体液输送”，其中 oxygen 和题干中的 blood 属于并列结构，符合题干关系，故填写。注意本句用词难度较高，如果考生要全部理解，做题难度会大。比如题干中的 liquid 在原文中被替换为 fluid，题干中的 carries 在原文中被替换为 transported。所以，更建议通过定位把握并列结构来做题，这样可以相对降低做题难度。
听前预测： 定位词为 mouth、teeth；提示词为 shaped like a，此处应填辅音开头的单数可数名词，内容应为对水熊虫口部形状的描述。
题目解析： 定位词 mouth 原词出现，提及 The tardigrade’s mouth is a kind of tube that can open outwards to reveal teeth-like structures known as ‘stylets’，意为“缓步动物的嘴是一种可以向外展开的管状结构，露出被称为‘口针’的牙齿状结构”。其中在 mouth 一词后面马上出现的 tube 符合预判及题干的用词搭配，故填写。后续听到 teeth 的描述，可进一步确认答案。
听前预测： 定位词为上一句中的 lake、plants；提示词为 resilient、low or high，此处应填名词，内容应为与 low or high 搭配的表达，并且能体现水熊虫较强的适应性。
题目解析： 定位词 lake 和 plants 原词出现后，考生可带着预判继续听。先听到 There’s been some interesting research which has found that tardigrades are capable of surviving radiation and very high pressure，意为“有一些有趣的研究发现，水熊虫能够在辐射和极高的压力下生存”，其中 pressure 似乎可以与题干中 high 一词搭配，可以先待定，然后等等看有没有出现 low 这一信息。继续听，听到 and they’re also able to withstand temperatures as cold as –200 degrees centigrade, or highs of more than 148 degrees centigrade, which is incredibly hot，意为“而且它们还能够承受低至零下 200 摄氏度的气温，或超过 148 摄氏度的高温，这已经是极其炎热的环境了”，其中 temperatures 更符合题干中的 very low or high 这一完整的信息搭配要求，因此把前一个 pressure 一词排除，故填写 temperatures。
听前预测： 定位词为上一句中的 metabolism 和本句中的 DNA；提示词为 A type of、ensures their DNA is not damaged，此处应填名词，内容应为搭配确保 DNA 不受损的信息。
题目解析： 本题定位词 metabolism 先原词出现，然后注意根据预判的词性和内容听取信息。先听到 They can remain like this until they are re-introduced to water, when they will come back to life in a matter of a few hours，意为“它们可以一直保持这种状态，直到重新回到水中，它们将在几个小时内苏醒”，此处没有出现可以搭配 DNA 的、符合预判的信息，继续听，考生可听到 While in a state of cryptobiosis, tardigrades produce a protein that protects their DNA，意为“在隐生状态下，水熊虫会产生一种保护其 DNA 的蛋白质”，其中 protein 一词搭配题干结构，且符合预判，故为正确答案。题干中的 not damaged 在原文中被替换为protects。
听前预测： 定位词为 Research；提示词为 underway、stay alive in，此处应填名词，内容应为搭配 stay alive in 的信息。
题目解析： 定 位 词 Research 在 原 文 中 被 替 换 为 experiment 及 tests。 其 中， 题 干 中 的underway 一词在原文中被替换为 currently，较为隐蔽，注意带着预判抓取核心信息判断答案。听到 There are currently several tests taking place in space, to determine how long tardigrades might be able to survive there. I believe the record so far is 10 days，意为“目前在太空中进行了几项测试，以确定水熊虫能够在太空中生存多长时间。我记得到目前为止的记录是 10 天”，其中 space 一词符合预判，先填写。继续听，听到题干用词 stay alive 在原文中被替换为 survive，how many days 在原文中被替换为 how long，因此，可进一步确认答案为 space。
听前预测： 定位词为 Feeding、moss；提示词为 or，此处应填名词，内容应与 moss 存在选择关系。
题目解析： 本题定位词 moss 原词出现，听到 They suck the juices from moss, or extract fluid from seaweed，意为“它们从苔藓中吸取汁液，或从海藻中汲取液体”，其中seaweed 和 moss 结构对称，符合预判，故填写。题干中的 liquids 在原文中被替换为 juices 和 fluid。
听前预测： 定位词为小标题 Conservation status；提示词为 not considered to be，此处无法准确判断词性，注意内容应搭配题干用词表达，且符合小标题对保护状态的描述。
题目解析： 本题定位词 Conservation status 原词出现，随后考生注意带着预判抓取核心信息。先听到 It is estimated that they have been in existence for approximately half a billion years and, in that time, they have survived five mass extinctions，意为“据估计，它们已经存在了大约 5 亿年，在此期间，它们在 5 次物种大灭绝中幸存下来”，其中没有符合题干的信息，继续听 So, it will probably come as no surprise to you, that tardigrades have not been evaluated by the International Union for Conservation of Nature and are not on any endangered list，意为“因此，这听起来或许并不让人惊讶：水熊虫未经国际自然保护联盟评估，也不在任何濒危名单上”，其中，先听到 evaluated，为题干中的 considered 这一信息的近义替换，随后听到的 endangered 符合预判，且态度方向与题干一致，故填写。
