托福考试听写训练营06-section 1-lecture 2
发布：常州环球雅思英语学校 点击数： 发布时间：2013-8-9 11:50:12
摘要: 常州环球雅思小编为大家带来托福听写训练营06-section1-lecture2，考生可以借鉴参考一下，以下是具体内容： narrator:listentopartofalectureinabiologyclass. 独白:请听下面生物
常州环球雅思小编为大家带来托福听写训练营 06-section 1-lecture 2，考生可以借鉴参考一下，以下是具体内容：
narrator :listen to part of a lecture in a biology class.
独白 :请听下面生物课的一部分录音。
professor :ok, i have an interesting plant species to discuss with you today.
教授 :今天我们将要讨论一种奇特的罕有植物品种:
um…it's a species of a very rare tree that grows in australia, eidothea hardeniana,
它就是生长于澳洲的eidothea hardeniana，
but it's better known as the nightcap oak.
也被称为夜冠橡树。
now, it was discovered only very recently, just a few years ago.
直到近几年人们才发现，
um… it remained hidden for so long because it's so rare.
夜冠橡树因其罕见而隐藏了很久，
there are only about 200 of them in existence.
目前存活个体仅有200株，
they grow in a rain forest, in a mountain rage…range in the north part of new south wales which is a…er… state in australia.
它们生长在澳大利亚新南威尔士州北部山脉的热带雨林区。
so just 200 individual trees in all.
所以目前存活个体仅有200株，
now another interesting thing about the nightcap oak is that it is…it represents…er…a very old type…er…kind of tree that grew a hundred million years ago.
而夜冠橡树的另一个奇特之处在于，它属于某种存活于一亿多年前的古老树种，
um, we found fossils that old that bear remarkable resemblance to the tree.
并与迄今发现的古老化石具有惊人的相似之处。
so, it's a primitive tree.
因此可以说它是原始植株，
a…a living fossil you might say.
你们也可以说它是活化石，
it's relic from earlier times and it has survived all these years without much change.
它是历经亿年风雨存活至今未曾改变的遗迹，
and it…it's probably a kind of tree from which other trees that grow in australia today evolved.
而且人们甚至可以推断，当今澳洲生长的诸多树种都是由其进化而来。
just to give you an idea of what we are talking about.
以上就是关于夜冠橡树的简介，
here's a picture of the leaves of the tree and its flowers.
下面请同学们观看一张它的树叶和花朵的照片。
i don't know how well you can see the flowers.
我不知道大家是否能看清楚花朵，
they're those little clusters sitting at the base of the leaves.
那些位于树叶底部的小花簇就是。
okay, what have we tried to find out about the tree since we've discovered it?
夜冠橡树在被发现后究竟有哪些谜题值得我们去探究呢?
hum…or how…why is…is it so rare? that's one of the first questions.
首先，为何它如此稀少?
um… how is it…um…how does it reproduce? this's another question.
另外，它是如何繁殖的呢?
um, maybe those two questions are actually related. jim?
也许这两个问题是紧密联系的。jim你怎么看?
student :hum …i don't know.
学生 :嗯，我不确定，
but i can imagine that…for instance, seed disposal might be a factor.
但我想种子的散播或许是影响橡树繁殖的重要因素。
i mean if the…er…you know, if the seeds cannot really disperse in the wild area, then, you know,
如果夜冠橡树的种子无法在广阔区域内散播、生长，
the tree may not colonize new areas.
那么树种就无法拓展新领域，
it can't spread from the area where it's growing.
因此其繁殖也就无法突破原生地的地理范围。
professor :right. that's…that's actually a very good answer.
教授 :好的，回答得很好。
um, of course, you might think there might not be any areas where the tree could spread into, er…because…um…well, it's very specialized in terms of the habitat.
同学们或许认为夜冠橡树能够生存的区域很稀有，即它对生长环境的要求很独特。
but, that's not really the case here.
但事实却并非如此。
um…the suitable habitat, that is, the actual rainforest is much larger than the few hectares where the nightcap oak grows.
实际上适合夜冠橡树生长的热带雨林区面积广阔，远远超过其现今存活的几公顷范围。
now this tree is a flowering tree as i showed you.
现在展现给你们的是一株开花树。
um…um…it produces a fruit, much like a plum.
大家想想看，夜冠橡树是开花植株，能够结出梅子状果实，
on the inside there's a seed with a hard shell.
其种子外包有坚硬的外壳。
it…it appears that the shell has to crack open or break down somewhat to allow the seed to soak up water.
只有在外壳被击破或打碎的情况下，种子才能接触到水分;
you know, if the nightcap oak remains…if their seeds remain locked inside their shell, they will not germinate.
你们清楚，如果夜冠橡树仍然在，一旦种子被封闭在外壳内，那么发芽生长就无法实现。
actually, the seeds…er…they don't retain the power to germinate for very long, maybe two years.
事实上，种子的发芽能力只能持续两年左右，
so there's actually quite a short window of opportunity for the seed to germinate.
所以实际上种子开始发芽的机会少之又少。
so the shell somehow has to be broken down before this…um…germination ability expires.
因此夜冠橡树的种子必须在此段时间内突破外壁。
and…and then there's a kind of rat that likes to feed on the seeds as well.
另外，当地某种鼠类喜欢以橡树种子为食。
so, given all these limitations, not many seeds that the tree produces will actually germinate.
因此，由于以上原因，仅有少数夜冠橡树种子能够成功地发芽生长，
so this is a possible explanation for why the tree does not spread.
所以这是对于这种树无法传播的可能解释。
it doesn't necessarily explain how it became so rare, but it explains why it doesn't increase.
这虽然不能解释夜冠橡树为何如此稀少，但或许可以说明为什么夜冠橡树繁殖如此有限，以至于数量无法激增。
ok, so it seems to be the case that the species, this nightcap oak is not very good at spreading.
综上所述，夜冠橡树似乎并不是善于扩展领地积极繁殖的物种，
however, it seems, though we can't be sure, that it's very good at persisting as a population.
虽然我们不能够肯定，但它的确是生命力极强的物种。
um…we…there's some indications to suggest that the population of the nightcap oak has not declined over the last er…you know, many hundreds of years.
部分证据显示，夜冠橡树的数量在过去的数百年内都未发生明显减少，
so it's stayed quite stable.
其个体数量极为稳定。
it's not a remnant of some huge population that is dwindled in last few hundred years for some reason.
因此，现存的200株并非数百年前丰盛繁殖的剩余，
it's not necessarily a species in retreat.
它也并不处于物种衰退期。
ok, so it cannot spread very well, but it's good at maintaining itself.
可以说，夜冠橡树繁殖力不强，但生命力强，
it's rare, but it's not disappearing.
它虽然稀少却并不面临灭绝的危险。
ok, the next thing we might want to ask about the plant like that is what chances does it have to survive into the future.
那么接下来我们将要讨论，夜冠橡树一类的植物种群在未来得以存活的几率有多大，
let's look at that.
让我们继续分析。
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