# 第四册 Lesson 26 The past life of the earth 地球上的昔日生命

## 一、课文原文

It is animals and plants which lived in or near water whose remains are most likely to be preserved, for one of the necessary conditions of preservation is quick burial, and it is only in the seas and rivers, and sometimes lakes, where mud and silt have been continuously deposited, that bodies and the like can be rapidly covered over and preserved. But even in the most favourable circumstances only a small fraction of the creatures that die are preserved in this way before decay sets in or, even more likely, before scavengers eat them. After all, all living creatures live by feeding on something else, whether it be plant or animal, dead or alive, and it is only by chance that such a fate is avoided. The remains of plants and animals that lived on land are much more rarely preserved, for there is seldom anything to cover them over. When you think of the innumerable birds that one sees flying about, not to mention the equally numerous small animals like field mice and voles which you do not see, it is very rarely that one comes across a dead body, except, of course, on the roads. They decompose and are quickly destroyed by the weather or eaten by some other creature.

It is almost always due to some very special circumstances that traces of land animals survive, as by falling into inaccessible caves, or into an ice crevasse, like the Siberian mammoths, when the whole animal is sometimes preserved, as in a refrigerator. This is what happened to the famous Beresovka mammoth which was found preserved and in good condition. In his mouth were the remains of fir trees — the last meal that he had before he fell into the crevasse and broke his back. The mammoth has now been restored in the Palaeontological Museum in St. Petersburg. Other animals were trapped in tar pits, like the elephants, saber-toothed cats and numerous other creatures that are found at Rancho La Brea, which is now just a suburb of Los Angeles. Apparently what happened was that water collected on these tar pits, and the bigger animals like the elephants ventured out on to the apparently firm surface to drink, and were promptly bogged in the tar. And then, when they were dead, the carnivores, like the sabre-toothed cats and the giant wolves, came out to feed and suffered exactly the same fate. There are also endless numbers of birds in the tar as well.

— ERROL WHITE, *The past life of the earth* from Discovery

## 二、重点词汇详解

| 单词 | 音标 | 词性 | 释义 | 用法说明 |
|------|------|------|------|----------|
| preservation | /ˌprezəˈveɪʃn/ | n. | 保存，防腐 | preserve v. 保存；preservation of food 食物保存 |
| silt | /sɪlt/ | n. | 淤泥，泥沙 | silt 淤泥（比mud更细的沉积物） |
| deposit | /dɪˈpɒzɪt/ | v. | 沉积，沉淀 | mud and silt deposited 泥沙沉积；名词：存款、押金 |
| decay | /dɪˈkeɪ/ | n./v. | 腐烂，衰败 | decay sets in 开始腐烂；tooth decay 蛀牙 |
| scavenger | /ˈskævɪndʒə/ | n. | 食腐动物 | scavengers eat them 食腐动物吃掉它们 |
| innumerable | /ɪˈnjuːmərəbl/ | adj. | 无数的，数不清的 | in- 否定前缀 + number + -able |
| vole | /vəʊl/ | n. | 田鼠 | field mice and voles 田鼠与野鼠 |
| decompose | /ˌdiːkəmˈpəʊz/ | v. | 分解，腐烂 | de- 分开 + compose 组成；decompose 有机物分解 |
| inaccessible | /ˌɪnækˈsesəbl/ | adj. | 难以接近的 | in- 否定 + accessible 可接近的 |
| crevasse | /krəˈvæs/ | n. | 裂缝，冰隙 | ice crevasse 冰隙 |
| mammoth | /ˈmæməθ/ | n. | 猛犸象 | Siberian mammoth 西伯利亚猛犸象 |
| palaeontological | /ˌpælɪɒntəˈlɒdʒɪkl/ | adj. | 古生物学的 | palaeo- 古 + ontology 学科 |
| bog | /bɒɡ/ | v. | 陷入泥沼 | bogged in the tar 陷入沥青中；be bogged down 陷入困境 |
| carnivore | /ˈkɑːnɪvɔː/ | n. | 食肉动物 | carni- 肉 + vore 吃；herbivore 食草动物 |

**专有名词：**
- **Beresovka mammoth**：别列佐夫卡猛犸象
- **Rancho La Brea**：拉布雷亚牧场（洛杉矶附近沥青坑遗址）
- **Palaeontological Museum in St. Petersburg**：圣彼得堡古生物博物馆

## 三、语法知识点

### 1. 强调句型 It is...that/who...

> **It is** animals and plants which lived in or near water **whose** remains are most likely to be preserved

强调句基本结构：It is/was + 被强调部分 + that/who/which + 句子其余部分

| 强调部分 | 例句 | 说明 |
|---------|------|------|
| 主语 | It is **he** who told me the news. | 强调主语 |
| 宾语 | It was **the book** that I bought yesterday. | 强调宾语 |
| 状语 | It was **in the park** that I met him. | 强调地点状语 |

本课特殊用法：It is...whose... 双重强调结构

### 2. whether 让步状语从句

> **whether it be** plant or animal, dead or alive

whether...be... 为虚拟让步从句，be 用原形，表示"无论是……"。

| 结构 | 例句 | 翻译 |
|------|------|------|
| whether it be A or B | Whether it be true or false, we must investigate. | 无论真假，我们必须调查 |
| whether...or... | Whether he agrees or not, we shall go ahead. | 无论他是否同意，我们都要继续 |

### 3. It is...that... 强调句与形式主语的区别

| 类型 | 结构 | 例句 |
|------|------|------|
| 强调句 | It is + 被强调部分 + that... | It is **quick burial** that is needed. |
| 形式主语 | It is + adj./n. + that从句 | It is **likely** that he will come. |

判断方法：去掉 It is...that... 后，若句子仍然完整，则为强调句。

### 4. before 时间状语从句

> before decay sets in or, even more likely, before scavengers eat them

before 引导时间状语从句，表示"在……之前"，此处暗含"来不及……就"。

## 四、重点句型分析

### 句型1：复杂强调句

> It is animals and plants which lived in or near water **whose** remains are most likely to be preserved

- 主干：It is...whose... 双重强调
- which lived in or near water 为定语从句修饰 animals and plants
- whose 引导定语从句修饰 remains

### 句型2：长难句——因果复合句

> It is only in the seas and rivers...where mud and silt have been continuously deposited, **that** bodies and the like can be rapidly covered over and preserved.

- 强调句：It is only in the seas and rivers...that...
- where 引导定语从句修饰 seas and rivers
- 被强调部分：地点状语

### 句型3：not to mention 插入补充

> the innumerable birds that one sees flying about, **not to mention** the equally numerous small animals

- not to mention 更不用说，用于补充说明
- 类似表达：let alone, much less

## 五、课文翻译

只有生活在水中或水边的动植物遗骸才最有可能被保存下来，因为保存的必要条件之一是迅速掩埋，而只有在泥沙不停淤积的海洋和江河里，有时在湖泊里，尸体之类的东西才能被迅速覆盖而保存下来。但即使在最有利的条件下，死去的生物中也只有一小部分在腐烂之前——或者更可能的是，在食腐动物吞食它们之前——能这样被保存下来。毕竟，一切生物都是靠吃别的东西来生存的，不管是植物还是动物，死的还是活的，只有碰巧才能避免这种命运。生活在陆地上的动植物遗骸被保存下来的可能性要小得多，因为很少有什么东西能覆盖它们。当你想到人们看到的无数飞翔的鸟儿，更不用说同样多的看不见的小动物如田鼠和野鼠，你就会发现很难遇到一具尸体，当然除了在道路上。它们腐烂后很快就被风化破坏或被其他动物吃掉。

陆地动物的遗迹之所以能保存下来，几乎总是由于某种非常特殊的条件，如掉进难以进入的洞穴，或掉进冰隙里，就像西伯利亚的猛犸象一样，有时整个动物都被保存了下来，就像放在冰箱里一样。著名的别列佐夫卡猛犸象就是这样被保存下来的，被发现时保存完好。它嘴里还有冷杉的残渣——这是它掉进冰隙折断脊柱之前的最后一顿饭。这头猛犸象现在已经在圣彼得堡的古生物博物馆中复原。其他动物则被困在沥青坑中，如在拉布雷亚发现的象、剑齿虎和许多其他动物，拉布雷亚现在只是洛杉矶的一个郊区。显然当时的情况是：沥青坑上积了水，像象这样的大动物冒险走到看似坚实的表面上喝水，结果立刻陷入沥青中。然后，当它们死后，食肉动物如剑齿虎和巨狼出来进食，也遭受了同样的命运。沥青中还有无数的鸟类。

## 六、语言点精讲

### 1. 写作手法：举例论证

- 作者通过具体案例（猛犸象、沥青坑）说明化石保存的特殊条件
- 每个例子都有详细的描述过程：原因→经过→结果

### 2. 逻辑结构

| 段落 | 主题 | 论证方法 |
|------|------|----------|
| 第一段 | 水生生物易保存，陆生生物难保存 | 对比论证 + 因果分析 |
| 第二段 | 陆生动物保存的特殊条件 | 举例论证（猛犸象 + 沥青坑） |

### 3. 文化背景

- 拉布雷亚沥青坑（Rancho La Brea Tar Pits）是世界上最著名的化石遗址之一
- 别列佐夫卡猛犸象于1900年在西伯利亚发现，保存极其完整
- 古生物学（Palaeontology）研究地球历史上的生命

### 4. 修辞分析

- "as in a refrigerator"——明喻，生动形象
- "suffered exactly the same fate"——讽刺意味，食腐动物也成了化石
- 强调句的反复使用增强了论证力度

## 七、课后练习要点

1. **词汇练习**：掌握 preservation、deposit、decay、scavenger、decompose 等核心词
2. **语法练习**：强调句型的辨认与构造；whether 虚拟让步从句
3. **翻译练习**：注意 It is...that... 强调句的翻译处理
4. **写作练习**：用举例论证法写一篇关于自然现象的说明文

## 八、本课小结

本课说明化石保存的条件与原理。核心观点：**水生生物因迅速掩埋而易保存，陆生动物仅在特殊条件下才能保存**。文章逻辑清晰：先论述一般规律（水生 vs 陆生），再以猛犸象和沥青坑为例说明特殊保存条件。语法重点为强调句型（It is...that/whose...）和 whether 虚拟让步从句。语言方面，注意 deposit、bog、carnivore 等地质学和生物学词汇。