The Human Body: Life Story 生命物语-8

I can see the muscles that make up my face, my skull¹, and my own brain. So, now I can take you on that journey into my ear in a way that’s never been possible before. This time we can fly straight through my eardrum. We're inside my head and at last I can show you what we’ve come here to see. On the right, it’s my eardrum again, but now we’re looking at it from the back. And attached to the middle of it is what I want to show you. It’s a bone. Though it’s towering above us, it’s actually tiny, about the size of a grain of rice. It’s the first in a chain of three bones which transfer the vibrations² of my eardrum to receptors in my cochlea. They are the smallest bones in my body and they are perfectly³ engineered to perform their task, yet these bones will reveal how evolution has transformed us because they were once something completely different. Let me take you back even before birth, and the bones will tell us their story: a fetus⁴ in the womb, just 12 weeks old and it’s only a few centimeters long, it would fit in an eggcup.

---Deep inside its head, its ear bones are forming. Now let’s look at younger and younger fetuses⁵: 8 weeks, 7 weeks, 6 weeks. We are actually witnessing something amazing because at certain times in this early development our human embryo⁶ betrays the shapes of the embryos⁷ of some of our distant prehuman ancestors. In other words, what we are looking at now is like the embryo of a creature we evolved from millions of years ago. It’s just as if we are journeying back in time virtually rewinding evolution to show episodes in the history of life.

---If we use the magnetic scanner, incredible details are revealed. We can see right through the skin of the brain and the spinal⁸ cord beginning to form, and the beginnings of an eye behind the emerging hand. Like some of the creatures that preceded us on the evolutionary⁹ tree, it has a curved spine¹⁰ and what might be a tail. And those amazing ear bones we saw earlier are taking shape on the outside of the head. The cells that will make them are located here, tiny grooves¹¹ almost hidden behind that hand.

words and expressions

tower:tower vi.
（常与above, up连用）高耸；屹立

cochlea:A spiral-shaped cavity of the inner ear that resembles a snail¹² shell and contains nerve endings essential for hearing.
耳蜗：内耳的螺旋形内腔，像蜗壳，有主要用于听的神经末梢

fetus: In human beings, the unborn young from the end of the eighth week after conception to the moment of birth, as distinguished¹³ from the earlier embryo.
胎儿：人类从开始怀孕的第八个星期到出生这一期间的有别于更早期的胚胎的幼儿

spinal cord :The thick, whitish cord of nerve tissue that extends from the medulla oblongata down through the spinal column and from which the spinal nerves branch off to various parts of the body.
脊髓：从延髓开始沿脊柱延伸的粘稠、白色、索状的神经组织，由脊髓开始脊椎神经分叉伸向身体各个部位

1 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

2 vibrations   

n.摆动( vibration的名词复数 )；震动；感受；（偏离平衡位置的）一次性往复振动

参考例句：

• We could feel the vibrations from the trucks passing outside. 我们可以感到外面卡车经过时的颤动。
• I am drawn to that girl; I get good vibrations from her. 我被那女孩吸引住了，她使我产生良好的感觉。 来自《简明英汉词典》

3 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

4 fetus   

n.胎，胎儿

参考例句：

• In the fetus,blood cells are formed in different sites at different ages.胎儿的血细胞在不同时期生成在不同的部位。
• No one knows why a fetus is not automatically rejected by the mother's immune system. 没有人知道为什么母亲的免疫系统不会自动排斥胎儿。

5 fetuses   

n.胎，胎儿( fetus的名词复数 )

参考例句：

• DNA was extracted from fetuses at mid-gestation, about 10 days past conception. DNA从受孕大约10天后的中期妊娠胚胎中提取。 来自互联网
• Brucellosis is a disease that causes fetuses to abort in cattle. 普鲁士菌病是一种可以导致牲畜胎儿夭折的疾病。 来自互联网

6 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

7 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

8 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

9 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

10 spine   

n.脊柱，脊椎；(动植物的)刺；书脊

参考例句：

• He broke his spine in a fall from a horse.他从马上跌下摔断了脊梁骨。
• His spine developed a slight curve.他的脊柱有点弯曲。

11 grooves   

n.沟( groove的名词复数 )；槽；老一套；（某种）音乐节奏v.沟( groove的第三人称单数 )；槽；老一套；（某种）音乐节奏

参考例句：

• Wheels leave grooves in a dirt road. 车轮在泥路上留下了凹痕。 来自《简明英汉词典》
• Sliding doors move in grooves. 滑动门在槽沟中移动。 来自《现代汉英综合大词典》

12 snail   

n.蜗牛

参考例句：

• Snail is a small plant-eating creature with a soft body.蜗牛是一种软体草食动物。
• Time moved at a snail's pace before the holidays.放假前的时间过得很慢。

13 distinguished   

adj.卓越的，杰出的，著名的

参考例句：

• Elephants are distinguished from other animals by their long noses.大象以其长长的鼻子显示出与其他动物的不同。
• A banquet was given in honor of the distinguished guests.宴会是为了向贵宾们致敬而举行的。