Unit  Two

Text A   Black  Holes

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一．课文简介

本文主要介绍了黑洞的概念，黑洞是怎样产生的，有关黑洞的一些研究。对于黑洞的研究才刚刚起步，因此黑洞对于我们来说还很神秘，需要我们的不断探索。

Paragraph 1                  What  is  a  black  hole  ?

Paragraph 2 – paragraph 4      The  theory  of  black holes

Paragraph 5            Endless  speculations  about  black  holes （老师停顿）

二．词汇精讲                   New  Words

（以下词汇精讲分别与上面表格中标蓝单词及词组链接）

词汇精讲：

1           escape  v. 逃跑，避免

A lion has escaped from its cage.

一头狮子从笼子里跑出来了

2   exert: vt. 用尽；尽力；运用；行使；施加

用法：exert pressure on sb.  给…施加压力

She exerted herself all year to earn good marks. 她整年努力以期获得好分数。

He’s been exerting a lot of pressure on me to change my mind. 他一直在施加种种压力要我改变主意。

操练：黑洞产生很强的引力。

      Black hole exert very strong gravity.

3  explode   v. 爆炸，突发

A bomb exploded at one of London’s busiest railway station this morning.

今天上午一颗炸弹在伦敦最繁忙的火车站爆炸了。

4  collapse  v.  n.  倒塌

例句参考第34页的word study 2

5  shrink: (shrank, shrunk ) v. 退缩；畏缩；收缩

用法： The gross national product shrank one percent last year. 去年国民生产总值减少了1%。

Washing wool in hot water will shrink it. 在热水中洗羊毛会使它缩水。

We will never shrink back before difficulties. 我们在困难面前决不退缩。

6         boundary  n.

We crossed the state boundary at midnight.

我们在午夜穿过了州界。

7         constant  adj.

He is in constant trouble with the police.

他总是不断和警察惹麻烦。

8         implication: n. 牵连；涉及；卷入；含意；暗示

派生词：imply v. 暗示，含意

用法：She seemed by implication to acknowledge that fact. 她似乎含蓄地承认了那事实。

      The implication of your statement is that I was wrong. 你这话的弦外之音是我错了。

9         launch: v.发射，发动

The launch of the third man-made satellite turned to be a great success. 第三枚航天器的发射结果是巨大成功。

操练：80年代我国发射了多颗卫星。

      In the 1980’s our country launched a number of satellites.

10     convincing : a. 令人信服的；有说服力的；

派生词：convince v. 使人信服，使… 相信

用法：She is very convincing . 她很令人信服。

convince sb. of sth. 使某人确信某事 ； convince sb. that 从句

We failed to convince him of his mistakes. 我们没能使他相信他是错误的。

Careful observation convinced them that it was so. 仔细的观察使他们相信情况是这样的。

11     companion : n. 同伴，同行，伴侣

派生词：company n. 同伴，陪伴 ； accompany v. 陪同，陪伴

用法：He is a good companion on the journey. 他是个好伴侣。

12     operate : v. 操作，运行，起作用，动手术

派生词：operation n. 操作

用法：The machine isn’t operating properly. 机器运转不正常。

He operated on the eyes of the patient. 他给病人的眼睛动了手术。

操练：药物开始见效了吗？

      Has the medicine started to operate ?

词组：phrases

1.       to research into  研究

She is researching into possible cures for AIDS.

她正在研究治疗艾滋病的方法。

2  speculation about : 关于… 的猜测

We heard all kinds of speculation about the cause of the President’s death. 我们听到关于总统死亡原因的种种猜测。

People have much speculation about the government’s intentions.  对政府的意图，人们作了许多猜测。

3  to swallow up : 吞没；并吞

His wife’s clothes bill swallowed up his wages . 老婆买的衣服耗尽了他的工资。

The fog swallowed up the whole city. 雾笼罩全城。

She swallowed the medicine with the help of some water. 她用水把药咽下了。

操练：他的身影消失在黑暗中。

       His figure was swallowed up in the dark.

4         to make use of ：利用

 We should make good use of our leisure time. 我们应该好好利用休闲时间。

  He was making full use of his opportunity. 他正充分利用他的机会。

5         to reduce … to  简化，归纳，迫使

Months’ bombing reduced the city to ruins.

几个月的轰炸使这个城市变成了废墟

6         to apply to  适用于

It does not apply to you.

它不适用于你。

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三．课文详解

                         Black Holes      (链接太空或地球的画面)

What is a black hole? Well, it’s difficult to answer this question, since the terms we would normally use to describe a scientific phenomenon are inadequate here. ①Astronomers and scientists think that a black hole is a region of space  (not a thing  ) into which matter has fallen and from which nothing can escape –not even light. ②So we can't see a black hole. A black hole exerts a strong gravitational pull and yet it has no matter. It is only space — or so we think. How can this happen?

The theory is that some stars explode when their density increases to a particular point; they collapse and sometimes a supernova occurs. ③From earth, a supernova looks like a very bright light in the sky which shines even in the daytime. Supernovae were reported by astronomers in the seventeenth and eighteenth centuries. Some people think that the Star of Bethlehem could have been a supernova. ④ The collapse of a star may produce a White Dwarf or a neutron star — a star, whose matter is so dense that it continually shrinks by the force of its own gravity. ⑤But if the star is very large (much bigger than our sun) this process of shrinking may be so intense that a black hole results. Imagine the earth reduced to the size of a marble, but still having the same mass and a stronger gravitational pull, and you have some idea of the force of a black hole. ⑥Any matter near the black hole is sucked in. It is impossible to say what happens inside a black hole. Scientists have called the boundary area around the hole the "event horizon." We know nothing about events which happen once objects pass this boundary. But in theory, matter must behave very differently inside the hole.

For example, if a man fell into a black hole, he would think that he reached the center of it very quickly.⑦ However an observer at the event horizon would think that the man never reached the center at all. Our space and time laws don't seem to apply to objects in the area of a black hole. Einstein's relativity theory is the only one which can explain such phenomena. Einstein claimed that matter and energy are interchangeable, so that there is no "absolute" time and space. There are no constants at all, and measurements of time and space depend on the position of the observer. They are relative. We do not yet fully understand the implications of the relativity theory; but it is interesting that Einstein's theory provided a basis for the idea of black holes before astronomers started to find some evidence for their existence.⑧ It is only recently that astronomers have begun specific research into black holes. ⑨In August 1977, a satellite was launched to gather data about the 10 million black holes which are thought to be in the Milky Way. And astronomers are planning a new observatory to study the individual exploding stars believed to be black holes.⑩

The most convincing evidence of black holes comes from research into binary star systems. Binary stars, as their name suggests,⑾ are twin stars whose position in space affects each other. In some binary systems, astronomers have shown that there is an invisible companion star, a "partner" to the one which we can see in the sky. Matter from the one which we can see is being pulled towards the companion star. Could this invisible star, which exerts such a great force, be a black hole? Astronomers have evidence of a few other stars too, which might have black holes as companions.

The story of black holes is just beginning. Speculations about them are endless. There might be a massive black hole at the center of our galaxy swallowing up stars at a very rapid rate.⑿ Mankind may one day meet this fate. On the other hand, scientists have suggested that very advanced technology could one day make use of the energy of black holes for mankind. These speculations sound like science fiction. But the theory of black holes in space is accepted by many serious scientists and astronomers. They show us a world which operates in a totally different way from our own ⒀ and they question our most basic experience of space and time. （老师停顿）

（以下课文详解与上面课文中划线部分内容相链接）

课文详解：

1   since 引导的是原因状语从句，定语从句we would normally use to describe a scientific phenomenon 修饰先行词the terms

2句中 “ into which” 而后 “ from which” 引导的从句为定语从句，修饰先行词space 。 如果which 在定语从句中作介词的宾语，那么这个介词可以提到从句前，构成“介词+which”引导的定语从句。这里注意两个搭配fall into ， escape from

3此句是复合句：that some stars explode when their density increases to a particular point 是表语从句；在表语从句中，when their density increases to a particular point 是时间状语。

注意to a particular point 是固定搭配表示“达到某一点”

此句讲了超新星supernova产生的步骤，注意有四个不及物动词vi. 的用法

explode    increase   collapse   occur

4． 有人认为圣诞星可能是一颗超新星。Could have + 过去分词 表示对以前发生的行为或动作的推测。

     I could have told you about it, but I don’t remember it now. 我可能给你说过这件事，但我现在记不得了。

5．whose 引导非限定性定语从句，修饰star

   注意 so… that 的用法

6.  该句的主要结构是“imagine… and you …”而“reduced … to marble ”和“having … pull”分别为过去分词和现在分词短语作定语，修饰the earth.

7．本句是表示与现在事实相反的虚拟语气。主句谓语动词用would think , 从句谓语动词用过去时fell 。

8. 此句中的it为形式主语，实际主语为that引导的主语从句

9. 此句是强调句，强调状语only recently. 强调结构为 It  is + 被强调部分 +  that …

10．exploding 和believed to be black holes 均为分词作定语，修饰stars。

11．As 的用法，引导非限定性定语从句

12  swallowing up stars at a very rapid rate是现在分词短语作定语，修饰hole

13  此句中which 引导限定性定语从句修饰world

注意介词 in 和 from 的用法，它们各自的搭配为 in a way和 different…from

课文译文

黑洞

黑洞是什么？这个问题很难回答，因为我们通常用来描述某一科学现象的术语不足以回答这个问题。天文学家和科学家都认为黑洞是一个太空区域（不是一种事物），落人其中的任何物质都无法逃逸——甚至包括光。所以我们看不见黑洞。一个黑洞能产生强大的吸力，但它却没有物质。它只是空间——或许是我们这么想的。这种现象是怎样发生的呢？

从理论来说，当某些恒星的密度增大到某种程度时就会发生爆炸，爆炸使它们崩溃，有时会产生超新星。从地球上看，一颗超新星看上去像是天空中的一盏明灯，甚至在白天也闪闪发光。超新星是由十七、十八世纪的天文学家发现的。有人认为圣诞星可能是一颗超新星。一颗超新星的崩溃可能会产生白矮星或中子星，其物资的密度非常大以至于在其自身重力的作用下持续收缩。但是，假如这颗恒星非常大（比我们的太阳大得多），那么，这种