---
url: https://gaojian.site/new-concept/book-4/20-snake-poison.md
description: 新概念英语第四册：Snake Poison。精读、词块回忆、双向译练、句法、逻辑与FSRS复习。
---

# 20 · 蛇毒

### 第1段

How it came about that snakes manufactured poison is a mystery. Over the periods their saliva, a mild, digestive juice like our own, was converted into a poison that defies analysis even today. It was not forced upon them by the survival competition; they could have caught and lived on prey without using poison, just as the thousands of non-poisonous snakes still do. Poison to a snake is merely a luxury; it enables it to get its food with very little effort, no more effort than one bite. And why only snakes? Cats, for instance, would be greatly helped; no running fights with large, fierce rats or tussles with grown rabbits—just a bite and no more effort needed. In fact, it would be an assistance to all carnivores though it would be a two-edged weapon when they fought each other. But, of the vertebrates, unpredictable Nature selected only snakes and one lizard. One wonders also why Nature, with some snakes, concocted poison of such extreme potency.
In the conversion of saliva into poison, one might suppose that a fixed process took place. It did not; some snakes manufactured a poison different in every respect from that of others, as different as arsenic is from strychnine, and having different effects. One poison acts on the nerves, the other on the blood.
The makers of the nerve poison include the mambas and the cobras and their venom is called neurotoxic. Vipers adders and rattlesnakes manufacture the blood poison, which is known as haemolytic. Both poisons are unpleasant, but by far the more unpleasant is the blood poison. It is said that the nerve poison is the more primitive of the two, that the blood poison is, so to speak, a newer product from an improved formula. Be that as it may, the nerve poison does its business with man far more quickly than the blood poison. This, however, means nothing. Snakes did not acquire their poison for use against man but for use against prey such as rats and mice, and the effects on these of viperine poison is almost immediate.

中文理解：蛇究竟是怎样产生毒液的，至今还是个谜。经过漫长的岁月，它们原本像人的唾液一样温和、具有消化作用的液体，变成了即使今天也难以分析透彻的毒液。这并不是生存竞争迫使它们发生的变化；不使用毒液，它们照样能捕食并生存，就像今天成千上万的无毒蛇一样。毒液对蛇来说，只是一种奢侈品：它让蛇几乎不费力就能获得食物，只需咬一口。可为什么偏偏是蛇呢？比如，猫如果有毒液，就会省事得多：不用追着又大又凶的老鼠搏斗，也不用与成年兔子厮打，只咬一口，就不必再费力。其实，所有食肉动物都能从中获益，尽管彼此争斗时，毒液会成为双刃剑。然而，难以捉摸的大自然，在脊椎动物中偏偏只选择了蛇和一种蜥蜴。人们也不免疑惑，为什么大自然让有些蛇拥有如此猛烈的毒液。
人们也许会以为，唾液转化为毒液经历的是同一种固定过程。事实并非如此。有些蛇产生的毒液，与另一些蛇的毒液在各方面都不同，就像砒霜与马钱子碱截然不同，产生的作用也不一样：一种作用于神经，另一种作用于血液。
产生神经毒液的蛇包括曼巴蛇和眼镜蛇，这类毒液被称为神经毒性毒液。蝰蛇、蝮蛇和响尾蛇产生的则是作用于血液的毒液，称为溶血性毒液。两类毒液都很可怕，但后者可怕得多。据说，神经毒液较为原始；打个比方，血液毒液像是根据改良配方制成的新产品。不管怎样，神经毒液作用于人体的速度，比血液毒液快得多。不过，这一点并不重要。蛇获得毒液，不是为了对付人，而是为了对付大小鼠类等猎物；蝰蛇的毒液对这些猎物几乎立即就能起效。

* **came about**：发生；形成；解释事情如何形成，不等于come across偶遇。

* **was converted into**：被转变成；into标记转变结果，不是转变的原因。

* **defies analysis**：难以分析透彻；defy在此是使解释难以奏效，不是人故意违抗。

* **forced upon**：强加给；upon较正式，强调被迫接受。

* **lived on prey**：靠猎物生存；on引出赖以生存的来源。

* **with very little effort**：几乎不费力；undefined

* **would be greatly helped**：本会大有帮助；在设想条件下描述受益者；这里不是报告猫已经获得这种帮助。

* **a two-edged weapon**：一把双刃武器；同一优势可能产生反作用，需说明两面分别是什么。

* **extreme potency**：极强的效力；undefined

* **a fixed process**：一种固定过程；undefined

* **in every respect**：在各个方面；respect这里是方面，不是尊敬。

* **as different as**：差别就像……一样大；undefined

* **acts on**：作用于；也可指根据建议行动，本课是生理作用对象。

* **neurotoxic**：神经毒性的；undefined

* **by far the more**：远为……的；强化差距；比较两者用the more，不必改成最高级。

* **so to speak**：可以这样说；标出比喻或不完全字面意义，不是事实证据。

* **Be that as it may**：尽管如此；承接后转向仍成立的主张，属于较正式让步表达。

* **for use against**：用于对付；介词说明用途环境或对象，不可互换。

#### How it came about that snakes manufactured poison is a mystery.

整个 How it came about that snakes manufactured poison 从句作 is a mystery 的主语。其中 it came about that…表示“……是怎样发生的”，it 是形式主语，that 从句承载发生的事情，即蛇产生毒液这一事实。因此，内层 that 从句是 came about 结构中的实际 主语，该主语从句为主谓宾结构，即 snakes manufactured poison.

#### Over the periods their saliva, a mild, digestive juice like our own, was converted into a poison that defies analysis even today.

复合句，主句为主谓宾结构，后面跟 that 引导的定语从句修饰 a poison，定语从句亦为主谓宾结构.

a mild, digestive juice like our own，整个是同位语成分，这里对此进行了细分.

#### It was not forced upon them by the survival competition; they could have caught and lived on prey without using poison, just as the thousands of non-poisonous snakes still do.

并列复合句，两句以分号隔开，第一句为主谓宾结构，第二句为双谓语，另有一个 as 引导的方式状语从句，该从句为主谓结构.

#### Poison to a snake is merely a luxury; it enables it to get its food with very little effort, no more effort than one bite.

并列句，两句以分号隔开，第一句为主系表结构，第二句为主谓宾+宾补结构， with…effort 为方式状语，后面 no more…bite 可以看作是 little effort 的同位语，具体描述一下有多轻松.

#### And why only snakes?

简单句，该句有所省略，还原可为：Why do only snakes have poison.

#### Cats, for instance, would be greatly helped; no running fights with large, fierce rats or tussles with grown rabbits—just a bite and no more effort needed.

并列句，该句以分号分成两部分，前一句为主谓结构，如果 helped 改为 helpful 则为主系表结构.

后句两个 with 所带为状语，因主语仍为 cats；而破折号后面完整句子为 a bite is needed and no more effort is needed. 主语已与 cats 不同，属于独立主格结构，可以理解成状语.

#### In fact, it would be an assistance to all carnivores though it would be a two-edged weapon when they fought each other.

复合句，该句主句为主系表结构，后面接一个 though 引导的让步状语从句，该从句亦为主系表结构，只不过在该从句中，还有一个 when 引导的时间状语从句，主谓结构.

#### But, of the vertebrates, unpredictable Nature selected only snakes and one lizard.

简单句，主谓宾结构.

#### But, of the vertebrates, unpredictable Nature selected only snakes and one lizard. One wonders also why Nature, with some snakes, concocted poison of such extreme potency.

复合句，主谓+宾语从句结构. why 引导的宾语从句为主谓宾结构. 此句表面是大自然调制的毒液，但 with 这个状语表明，大自然是借蛇之口，调制出的毒液.

#### In the conversion of saliva into poison, one might suppose that a fixed process took place.

复合句，主谓+宾语从句结构. 从句本身为主谓结构.

#### It did not; some snakes manufactured a poison different in every respect from that of others, as different as arsenic is from strychnine, and having different effects.

并列复合句，以分号分开，首句为主谓结构. 第二句主句为主谓宾结构，后面为从句本身为主谓结构.

有三个结构修饰 a poison，其中第一个可改语序为(different from that of others) \[in every respect]. 第二个修饰结构为 as different as 引导的方式状语从句，从句本身是主系表结构. 第三个为现在分词短语作后置定语，表示效果完全不同.

#### One poison acts on the nerves, the other on the blood.

并列句，不过因为后句是省略句，划分了成分.

如果是两个完整的句子，则不能像本句一样直接以逗号相连，须加 and 才可以. 还原为 one poison acts on the nerves, and the other acts on the blood.

#### The makers of the nerve poison include the mambas and the cobras and their venom is called neurotoxic.

并列句，and 连接两个句子，第一句为主谓宾结构，第二句为主谓+主语补语.

We call their venom . 宾语补足语在被动语态时，转为主语补足语.

#### Vipers adders and rattlesnakes manufacture the blood poison, which is known as haemolytic.

复合句，主句为主谓宾结构，后有一个 which 引导的定语从句，该从句为被动语态的主谓+主语补语结构.

#### Both poisons are unpleasant, but by far the more unpleasant is the blood poison.

并列句，but 连接两个句子，均为主系表结构.

#### It is said that the nerve poison is the more primitive of the two, that the blood poison is, so to speak, a newer product from an improved formula.

复合句，实际主语为两个 that 引导的主语从句. 两个主语从句均为主系表结构.

so to speak 为 so to say 的变体.

#### Be that as it may, the nerve poison does its business with man far more quickly than the blood poison.

复合句，句首是一个倒装的让步状语从句，还原为 as(此时应用 though) it may be that. 在 as 引导让步状语从句中，表语放在句首时，若主语是代词，主谓不倒装，但是必须把作表语的形容词、名词、动词和副词提到 as 前面. 所以文中仍为 it may，只是将 be that 提前.

主句为主谓宾结构.

#### This, however, means nothing.

简单句，主谓宾结构.

#### Snakes did not acquire their poison for use against man but for use against prey such as rats and mice, and the effects on these of viperine poison is almost immediate.

并列句，前句为主谓宾结构，后句为主系表结构.

## 学完这一课

把一个“如何形成”的疑问作为完整句子的主语。

[Nce · 本册复习台](/new-concept/book-4/review) · [三册选择地图](/new-concept/)

*译文依据整理稿，由本站按中文表达重新校订；解析据吴应时整理资料及首轮审校稿；词伙与练习提示为本站学习设计。原PDF第80—83页，2022年2月第2版。*