英语听力：探索发现 2012-07-08 恐龙是怎样的炼成的—22
时间：2019-01-23 作者：英语课 分类：探索与发现2012年
英语课
Going back, say, ten years ago, would you ever imagine that you would have been able to tell what colour any dinosaurs 2 would have been?
No, I mean I think at that time I would have said that it’s one of the things we will never know. And so we just focus up and see what we’ve got here.
Using a scanning electron microscope, Mike can find clues about the pigmentation of these ancient fossil feathers.
And if we just have a look at this, the required time amount of locations, that’s 9,000 times. All these sausage shapes then are melanosomes, and then a living feather. They would be full of the chemical melanin, which would in fact give the colour. And these sausage-shaped ones are a sure indicator 4 of a particular kind of melanin, which is the one that gives a black or dark brown colour. So in some cases like this, the field of views is completely packed with the sausage-shaped ones. So we know this must have been intensely black. If they were more loosely spaced, we would know it was a paler colour, maybe dark brown or even gray.
So is it just really the presence or absence of the black pigments 5 that you are able to ascertain 6?
Well, the wonderful thing is there is another form of melanin that gives a ginger 7 colour. And so, and it is packaged in a different shape of melanosome, not this kind of cigar-shaped or sausage-shaped one, but a spherical 8 one, a little ball. Close it up. We get the vacuum going.
A sample taken from a different fossil shows what the structures that carried this ginger pigment 3 look like.
That's entirely 9 different. This surface looks as if they've taken a melon baller and scooped 10 up lots of little spherical hollows. So what colour would these melanosomes have made?
This is definitely ginger. And if you look at this ginger hair from a man of our human being, that's what you see ourselves.
So is it relatively 11 easy to compare your dinosaur 1 feathers with what’s already known about, the feathers of a living bird, to get that comparison to know what colours you were looking at here?
We can put the specimens 12 in one after the other. There is the modern one. There is the fossil. Spot the difference. No difference at all. And who on earth would have thought a dinosaur was close to a bird? But here we are, you know, it's kind of proved in the skeletons. And now if you like, proved in the melatonin of the feathers.
n.恐龙
- Are you trying to tell me that David was attacked by a dinosaur?你是想要告诉我大卫被一支恐龙所攻击？
- He stared at the faithful miniature of the dinosaur.他凝视著精确的恐龙缩小模型。
n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西
- The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
- Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》
n.天然色素，干粉颜料
- The Romans used natural pigments on their fabrics and walls.古罗马人在织物和墙壁上使用天然颜料。
- Who thought he might know what the skin pigment phenomenon meant.他自认为可能知道皮肤色素出现这种现象到底是怎么回事。
n.指标；指示物，指示者；指示器
- Gold prices are often seen as an indicator of inflation.黃金价格常常被看作是通货膨胀的指标。
- His left-hand indicator is flashing.他左手边的转向灯正在闪亮。
n.（粉状）颜料( pigment的名词复数 )；天然色素
- The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
- The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句
vt.发现，确定，查明，弄清
- It's difficult to ascertain the coal deposits.煤储量很难探明。
- We must ascertain the responsibility in light of different situtations.我们必须根据不同情况判定责任。
n.姜，精力，淡赤黄色；adj.淡赤黄色的；vt.使活泼，使有生气
- There is no ginger in the young man.这个年轻人没有精神。
- Ginger shall be hot in the mouth.生姜吃到嘴里总是辣的。
adj.球形的；球面的
- The Earth is a nearly spherical planet.地球是一个近似球体的行星。
- Many engineers shy away from spherical projection methods.许多工程师对球面投影法有畏难情绪。
ad.全部地，完整地；完全地，彻底地
- The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
- His life was entirely given up to the educational work. 他的一生统统献给了教育工作。
v.抢先报道( scoop的过去式和过去分词 )；（敏捷地）抱起；抢先获得；用铲[勺]等挖（洞等）
- They scooped the other newspapers by revealing the matter. 他们抢先报道了这件事。 来自《简明英汉词典》
- The wheels scooped up stones which hammered ominously under the car. 车轮搅起的石块，在车身下发出不吉祥的锤击声。 来自《简明英汉词典》
adv.比较...地，相对地
- 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。