The past life of the earth

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 sit have been continuously deposited, that bodies and the 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 bout, 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 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--

译文

正是生活在水里或水边的动物和植物，其遗骸最有可能被保存下来，因为保存的必要条件之一是快速掩埋，而只有在海洋、河流，有时是湖泊中——那里泥沙不断沉积——生物的遗体才能迅速被覆盖并保存。

但即使在最有利的条件下，死去的生物中也只有一小部分能以这种方式被保存下来，在腐烂开始之前，或者更可能的是，在食腐动物吃掉它们之前。毕竟，所有生物都靠摄取其他东西为生，无论是植物还是动物，是死的还是活的，只有靠偶然的机会才能避免这样的命运。生活在陆地上的植物和动物遗骸保存得要少得多，因为很少有东西能将它们覆盖起来。当你想到无数飞来飞去的鸟儿，更不用说那些同样众多的、你看不见的小动物，如田鼠和田鼠（vole），你会发现极少遇到一具尸体，当然，除了在道路上。它们会腐烂，并很快被天气破坏或被其他生物吃掉。

陆地动物的遗迹几乎总是由于某些非常特殊的境况才得以保存下来，例如掉进难以进入的洞穴，或是落入冰隙中，就像西伯利亚的猛犸象那样，有时整个动物都能被保存下来，就如同放在冰箱里一样。这就是著名的别列索夫卡猛犸象所发生的事——它被发现时保存完好，状态良好。在它的嘴里，有冷杉树的残余——那是他掉进冰隙摔断脊背前的最后一餐。那个猛犸象坑如今就在洛杉矶的一个郊区。显然，事情是这样的：水积聚在这些焦油坑上，较大的动物如大象冒险走到那看似坚固的表面去喝水，结果立刻陷进焦油里。然后，当它们死后，食肉动物如剑齿虎和巨型狼前来进食，也遭受了同样的命运。那里还有无数的鸟类也被困在焦油中。

--ERROL WHITE The past life of the earth from Discovery--

词汇表

preserved

动词, 形容词

英:/prɪˈzɜːvd/

美:/prɪˈzɝːvd/

定义

1. 保存 - To keep something in its original state or prevent it from decaying.

例子: The ancient fossils were preserved in the tar pits for thousands of years.

例子: Scientists preserved the mammoth's body in a frozen state.

2. 保持不变 - Maintained in an unchanged condition.

例子: The remains of the plants were well preserved due to quick burial.

例子: This museum piece has been preserved for educational purposes.

近义词

conserved: 强调主动保护资源或环境，常用于正式或科学语境，而 'preserved' 更侧重于物理保存。

maintained: 更通用，适用于日常维护，如建筑物，而 'preserved' 常暗示历史或自然保存。

protected: 侧重于防范破坏或威胁，而 'preserved' 强调保持原有状态，不一定涉及外部威胁。

反义词:

destroyed, decayed, ruined

用法

常用于科学、历史或自然语境中描述防止腐烂或变化的过程，例如在化石学中搭配 'well preserved'；文化背景中，可能涉及博物馆或考古。

形式:

过去式: preserved, 名词形式: preservation, 形容词形式: preservable

关键句型 "It is [subject] that [clause]"

定义

此句型是一种强调句型，用于突出句子的特定部分，比如主语、宾语或时间。基本结构为：It is + [subject]（强调的部分）+ that + [clause]（剩余句子）。根据《剑桥英语语法手册》，这种结构源于英语的强调句形式，帮助说话者强调重要信息，使句子更具焦点。例如，在文章中：“It is animals and plants which lived in or near water whose remains are most likely to be preserved.” 这里强调了“animals and plants which lived in or near water”作为关键主题。

它常用于正式写作或口语中，增强表达的精确性。

用法

此句型主要用于强调句子中的某个元素，而非改变整体含义。使用场景包括科学文章、新闻报道或日常对话中突出事实。规则：It is 后跟被强调的部分，然后用 that 引导剩余从句。横向比较：与简单句相比，此句型更正式，能突出细节；与 "What I want to say is that..." 相比，它更简洁高效。与其他语法点联系，如关系从句（例如文章中的 "which lived"），它可以结合使用，形成更复杂的句子结构。同时，与条件句（如 "If it is..."）不同，此句型不涉及假设，而是直接强调事实。

在语法体系中，它属于句型转换工具，帮助学生从基本句扩展到高级表达。跨语法联系：学生可将其与疑问句（如 "Is it [subject] that...?"）结合，练习强调在问答中的应用。

注意事项

学生常犯的错误包括：误用 that 为其他连词，如 which 或 who，导致句子逻辑混乱；或忘记 that，使句子变成普通陈述句，失去强调效果。纠正建议：练习时，先识别句子中想强调的部分，再构建结构。例如：

错误示例：Animals and plants which lived in or near water whose remains are most likely to be preserved.  （缺少强调，显得平淡）
正确示例：It is animals and plants which lived in or near water that whose remains are most likely to be preserved.  （正确强调关键部分）

另一个常见问题是用在非正式场合显得生硬，建议在写作中多练习以适应语境。

练习

原创例子：假设你在讨论环境问题，可以说：“It is plastic waste that is harming our oceans the most.” 学生可替换 [subject] 为 “deforestation” 并调整 [clause]，如：“It is deforestation that is causing climate change.” 这能帮助你在辩论或报告中应用此句型，增强说服力。通过替换关键词，学生可以练习在不同主题如科学或日常生活中的使用，例如在课堂讨论中说：“It is hard work that leads to success.”

这种练习能加深对句型的掌握，并鼓励自然融入对话。

额外内容

背景知识：强调句型起源于古英语的句法演变，常在现代英语中用于正式文本，如科学文章。文化对比：与中文的强调方式（如用“就是”）类似，但英语更依赖结构而非词汇。与法语的强调句（如 "C'est ... que"）相似，均通过特定格式突出重点。这有助于学生理解英语在全球语境中的表达多样性，进而提升跨文化沟通能力。