英语听力：自然百科 探索世界奥秘之Life Story(生命物语) Unit4

探索世界奥秘之Life Story(生命物语) Unit4

Everything that's alive and quite a few things that aren't, gives off heat. That's what you are looking at now. Every part of your body is burning up energy and creating heat as it goes about the business of being you. But the hottest bit of you is up here, your brain is burning up more energy than anything else in your body, almost a fifth of all the calories you eat and drink. And it uses up almost the same amount whether you are concentrating on something really difficult or just wondering whether to put the cat out, because day and night, your brain is challenged with the most difficult task it will ever face, keeping you alive. 

Right now for instance, there are quite a few things on your mind, tonight's dinner for example. For starters, your brain is coordinating¹ a major haulage operation. 

Even though the route is usually downhill, food doesn't fall from your mouth to your stomach. When your brain tells you to swallow, it triggers waves of muscle contractions³. They squeeze things along in your esophagus at around 4 centimeters per second. 

The first scheduled stop is the stomach. It's essentially⁴ a biological liquidizer. Its lining⁵ is covered in delicate folds which allow it to expand with each mouthful. Inside a mixture of enzymes⁶ and hydrochloric acid start to digest your food. And very probably your dinner is still in there, it churns away for about 4 hours. Soon it will be released into your small intestine⁷ and at a cue from your brain, bile will be added. This will help you break down fats. You will be carrying tonight's dinner for about 24 hours, so I hope you liked it. When it does finally leave you, it will take around 25 grams of dead cells from your gut⁸ with it. 

But don't worry, you are constantly replacing cells from head to toe. 

Your brain is managing the body's workforce⁹ of approximately 50, 000 billion cells and most of them don't last more than a few years. Cells are constantly dying and being replaced by new ones. Up to a billion new cells for old every hour. What this really means is that most parts of your body are in fact a good deal younger than you are. But remarkably¹⁰ these cells aren't replaced and they are particularly special. Each one has a natural tendency to twitch¹¹. 

words and expressions

haulage:The act or process of hauling.

拖拽的行为或过程

muscle contraction²:肌肉收缩

esophagus: The muscular, membranous¹² tube for the passage of food from the pharynx to the stomach; the gullet.食道

lining:A covering or coating for an inside surface:衬里,内层

enzyme:Any of numerous proteins or conjugated¹³ proteins produced by living organisms and functioning as biochemical catalysts¹⁴.

酶：由活的有机体产生的各种蛋白质或蛋白质结合体的一种，起生物催化剂的作用

hydrochloric acid :盐酸

churn:搅拌, 搅动

small intestine:小肠

bile:胆汁

1 coordinating   

v.使协调，使调和( coordinate的现在分词 )；协调；协同；成为同等

参考例句：

• He abolished the Operations Coordinating Board and the Planning Board. 他废除了行动协调委员会和计划委员会。 来自辞典例句
• He's coordinating the wedding, and then we're not going to invite him? 他是来协调婚礼的，难道我们不去请他？ 来自电影对白

2 contraction   

n.缩略词，缩写式，害病

参考例句：

• The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
• The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。

3 contractions   

n.收缩( contraction的名词复数 )；缩减；缩略词；（分娩时）子宫收缩

参考例句：

• Contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
• Muscle contractions are powered by the chemical adenosine triphosphate(ATP ). 肌肉收缩是由化学物质三磷酸腺苷(ATP)提供动力的。 来自辞典例句

4 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

5 lining   

n.衬里，衬料

参考例句：

• The lining of my coat is torn.我的外套衬里破了。
• Moss makes an attractive lining to wire baskets.用苔藓垫在铁丝篮里很漂亮。

6 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

7 intestine   

adj.内部的；国内的；n.肠

参考例句：

• This vitamin is absorbed through the walls of the small intestine.这种维生素通过小肠壁被吸收。
• The service productivity is the function,including external efficiency,intestine efficiency and capacity efficiency.服务业的生产率是一个包含有外部效率、内部效率和能力效率的函数。

8 gut   

n.[pl.]胆量；内脏；adj.本能的；vt.取出内脏

参考例句：

• It is not always necessary to gut the fish prior to freezing.冷冻鱼之前并不总是需要先把内脏掏空。
• My immediate gut feeling was to refuse.我本能的直接反应是拒绝。

9 workforce   

n.劳动大军，劳动力

参考例句：

• A large part of the workforce is employed in agriculture.劳动人口中一大部分受雇于农业。
• A quarter of the local workforce is unemployed.本地劳动力中有四分之一失业。

10 remarkably   

ad.不同寻常地，相当地

参考例句：

• I thought she was remarkably restrained in the circumstances. 我认为她在那种情况下非常克制。
• He made a remarkably swift recovery. 他康复得相当快。

11 twitch   

v.急拉，抽动，痉挛，抽搐；n.扯，阵痛，痉挛

参考例句：

• The smell made my dog's nose twitch.那股气味使我的狗的鼻子抽动着。
• I felt a twitch at my sleeve.我觉得有人扯了一下我的袖子。

12 membranous   

adj.膜的，膜状的

参考例句：

• Others are born live, after struggling to break free from a membranous egg sac. 其余的是冲破膜状蛋囊而出生的。 来自电影对白
• Thellos thellon, membranous layer of life is our only home. 薄薄的膜层就是咱们独一的家园。 来自互联网

13 conjugated   

adj.共轭的，成对的v.列出（动词的）变化形式( conjugate的过去式和过去分词 )；结合，联合，熔化

参考例句：

• Hemoglobin can also be cross-linked to solublepolymers to form so-called conjugated hemoglobin. 血红蛋白也能交联到水溶性多聚体上，形成所谓的共轭血红蛋白。 来自《简明英汉词典》
• Similar delocalization is found in other conjugated systems. 在其他共轭体系中，也发现类似的离域。 来自辞典例句

14 catalysts   

n.催化剂( catalyst的名词复数 )；触媒；促进因素；有感染力的人

参考例句：

• The first catalytic converters were called conventional oxidation catalysts. 最初的转化器叫做常规氧化催化器。 来自辞典例句
• Many processes that are essential to the chemical industry use heterogeneous catalysts. 很多重要的化学工业过程就是使用多相催化剂的。 来自辞典例句