Lesson 38 Water and the traveller
课文：
1. Contamination of water supplies is usually due to poor sanitation close to water sources, sewage disposal into the sources themselves, leakage of sewage into distribution systems or contamination with industrial or farm waste.
- 句子类型
- 核心结构：主语(Contamination of water supplies) + 系动词(is) + 表语(due to...)
- 语法要点：① 主语为抽象名词短语，of water supplies 作后置定语修饰 Contamination；② due to 后接四个并列的名词短语（poor sanitation/sewage disposal/leakage of sewage/contamination with...），构成并列的原因宾语；③ close to water sources 为形容词短语作后置定语，修饰 poor sanitation。
- 释义：水源的污染通常是由于接近水源的地方卫生条件太差、污水排入水源本身、污水渗入给水系统或工农业废弃物造成的污染。
2. Even if a piped water supply is safe at its source, it is not always safe by the time it reaches the tap.
- 句子类型：复合句（让步状语从句 + 时间状语从句 + 主句）
- 核心结构：让步状语从句(Even if...) + 主句(it is not always safe...) + 时间状语从句(by the time...)
- 语法要点：① Even if 引导让步状语从句（主系表结构），表 “即使”；② by the time 引导时间状语从句，从句用一般现在时 (reaches) 表将来，符合 “时间状语从句主将从现” 规则；③ 主句中 it 为形式主语，指代前文的 a piped water supply。
- 释义：即使管道供水系统在水源处是安全的，等水到达水龙头时就不一定安全了。
3. Intermittent tap-water supplies should be regarded as particularly suspect.
- 句子类型
- 核心结构：主语(Intermittent tap-water supplies) + 情态动词被动式(should be regarded) + 介词短语作补语(as particularly suspect)
- 语法要点：① 固定搭配regard...as...（把…… 视为……）的被动形式 be regarded as...；② particularly 为副词作状语，修饰形容词 suspect。
- 释义
4. Travellers on short trips to areas with water supplies of uncertain quality should avoid drinking tap-water, or untreated water from any other source.
- 句子类型
- 核心结构：主语(Travellers) + 谓语(should avoid) + 宾语(drinking tap-water, or untreated water...)
- 语法要点：① 主语后接多层后置定语：on short trips（介词短语）→ to areas（介词短语）→ with water supplies（介词短语）→ of uncertain quality（介词短语），层层修饰 Travellers；② 谓语为avoid doing sth（避免做某事），动名词 drinking 作宾语；③ from any other source 为介词短语作后置定语，修饰 untreated water。
- 释义：短途前往水质不明地区的旅行者，应避免饮用自来水或其他任何来源的未经处理的水。】
5. It is best to keep to hot drinks, bottled or canned drinks of well-known brand names—international standard of water treatment are usually followed at bottling plants.
- 句子类型
- 核心结构 1：形式主语 It + 系动词 is + 表语 best + 真正主语 to do 不定式(to keep to...)核心结构 2：主语(international standard...) + 被动谓语(are usually followed) + 地点状语(at bottling plants)
- 语法要点：① 前半句用It is + 形容词 + to do 句式，It 为形式主语，避免真正主语过长导致句子头重脚轻；② bottled or canned 为过去分词作定语，修饰 drinks；of well-known brand names 为介词短语作后置定语，修饰 drinks；③ 破折号后为独立简单句，用被动语态表 “装瓶厂遵循标准”，突出动作的承受者（international standard）；④ standard 此处为可数名词，实际应为standards（语法小瑕疵，表 “各类标准”）。
- 释义：最好只饮用开水、名牌瓶装或罐装饮料 —— 装瓶厂通常都会遵循国际水处理标准。
6. Carbonated drinks are acidic, and slightly safer.
- 句子类型
- 核心结构：主语(Carbonated drinks) + 系动词 are + 表语 1 (acidic) + and + 表语 2 (slightly safer)
- 语法要点：① and 连接两个并列的表语，省略了重复的系动词 are 和主语；② slightly 为副词作状语，修饰比较级 safer（隐含与普通饮用水 / 非碳酸饮料的对比）。
- 释义
7. Make sure that all bottles are opened in your presence, and that their rims are clean and dry.
- 句子类型
- 核心结构：祈使句谓语(Make sure) + 宾语从句 1(that...) + and + 宾语从句 2(that...)
- 语法要点：① 祈使句以动词原形 Make 开头，表建议 / 要求，主语 you 省略；② make sure 后接that 引导的宾语从句，第一个 that 可省，第二个 that 为避免歧义不可省；③ 两个宾语从句均为被动语态（are opened/are clean and dry），in your presence 为介词短语作状语，表 “当着你的面”。
- 释义：确保所有瓶子都是当着你的面开启的，且瓶口清洁、干燥。
8. Boiling is always a good way of treating water.
- 句子类型
- 核心结构：主语(Boiling) + 系动词 is + 表语(a good way) + 后置定语(of treating water)
- 语法要点：① 主语为动名词 Boiling，表 “烧开水” 这一行为，作主语时谓语用单数；② of treating water 为介词短语作后置定语，修饰 way。
- 释义
9. Some hotels supply boiled water on request and this can be used for drinking, or for brushing teeth.
- 句子类型：并列复合句（and 连接两个简单句，第二个为被动语态）
- 核心结构 1：主语(Some hotels) + 谓语(supply) + 宾语(boiled water) + 状语(on request)核心结构 2：主语(this) + 情态动词被动式(can be used) + 目的状语(for drinking, or for brushing teeth)
- 语法要点：① boiled 为过去分词作定语，修饰 water，表 “被烧开的”；② on request 为固定搭配，作状语表 “根据要求”；③ this 指代前文的 boiled water；for drinking/for brushing teeth 为并列的介词短语作目的状语。
- 释义：有些酒店可根据要求提供开水，这些开水可用于饮用和刷牙。
10. Portable boiling elements that can boil small quantities of water are useful when the right voltage of electricity is available.
- 句子类型
- 核心结构：主句(Portable boiling elements...are useful) + 定语从句(that...) + 时间状语从句(when...)
- 语法要点：① that 引导限制性定语从句，修饰先行词 Portable boiling elements，that 在从句中作主语；② small quantities of 为固定搭配，表 “少量的”，后接不可数名词 water；③ when 引导时间状语从句（主系表结构），available 为形容词作表语，表 “可获得的”。
- 释义：如果能获得适配的电压，可烧少量水的便携式加热装置会非常实用。
11. Refuse politely any cold drink from an unknown source.
- 句子类型
- 核心结构：谓语(Refuse) + 状语(politely) + 宾语(any cold drink) + 后置定语(from an unknown source)
- 语法要点：① 祈使句以动词原形 Refuse 开头，主语 you 省略；② politely 为副词作状语，修饰 Refuse，置于谓语和宾语之间（也可放句首 / 句尾）；③ from an unknown source 为介词短语作后置定语，修饰 any cold drink。
- 释义
12. Ice is only as safe as the water from which it is made, and should not be put in drinks unless it is known to be safe.
- 句子类型：并列复合句（and 连接两个分句，含定语从句 + 条件状语从句）
- 核心结构 1：主语 (Ice) + 系动词 (is) + 表语 (as safe as the water...) + 定语从句 (from which...)核心结构 2：主语 (Ice，省略) + 情态动词被动式 (should not be put) + 状语 (in drinks) + 条件状语从句 (unless...)
- 语法要点：① as...as... 原级比较结构，表 “和…… 一样安全”；② from which 引导介词 + 关系代词的定语从句，修饰先行词 the water，which 指代 the water，从句还原为 it is made from the water；③ unless 引导条件状语从句，表 “除非”，相当于 if...not；④ 第二个分句为被动语态，省略了重复的主语 Ice；it is known to be safe 中，it 指代 Ice，to be safe 为不定式作主语补足语。
- 释义：冰块的安全性完全取决于制作它的水，除非确认冰块是安全的，否则切勿加入饮料中。
13. Drinks can be cooled by placing them on ice rather than adding ice to them.
- 句子类型
- 核心结构：主语 (Drinks) + 情态动词被动式 (can be cooled) + 方式状语 (by placing...rather than adding...)
- 语法要点：① by 为介词，后接动名词作方式状语，表 “通过某种方式”；② rather than 连接两个并列的动名词（placing/adding），表 “而不是”；③ 两个 them 均指代 Drinks，避免重复。
- 释义：可以把饮料放在冰块上冷却，而不是将冰块加入饮料中。
14. Alcohol may be a medical disinfectant, but should not be relied upon to sterilize water.
- 句子类型：并列复合句（but 连接两个主系表 / 被动结构，表转折）
- 核心结构 1：主语 (Alcohol) + 情态动词系动词 (may be) + 表语 (a medical disinfectant)核心结构 2：主语 (Alcohol，省略) + 情态动词被动式 (should not be relied upon) + 不定式作补语 (to sterilize water)
- 语法要点：① but 表转折，连接两个并列分句，第二个分句省略重复的主语 Alcohol；② rely upon 为固定搭配，被动形式为 be relied upon，后接不定式 to do作目的补语；③ medical 为形容词作定语，修饰 disinfectant。
- 释义：酒精可作为医用消毒剂，但绝不能依靠它来对饮用水进行消毒。
15. Ethanol is more effective at a concentration of 50-70 percent; below 20 per cent, its bactericidal action is negligible.
- 句子类型
- 核心结构 1：主语 (Ethanol) + 系动词 (is) + 表语 (more effective) + 状语 (at a concentration of 50-70 percent)核心结构 2：状语 (below 20 per cent) + 主语 (its bactericidal action) + 系动词 (is) + 表语 (negligible)
- 语法要点：① more effective 为比较级，隐含 “与其他浓度相比” 的含义；② at a concentration of 为固定搭配，表 “在…… 浓度下”；③ 分号替代 and，连接两个语义对比的句子；below 20 per cent 为介词短语作状语，表 “在 20% 的浓度以下”；④ bactericidal 为合成形容词（bacteria+cid+al），作定语修饰 action，表 “杀菌的”。
- 释义：乙醇在浓度为 50% 至 70% 时杀菌效果最佳；浓度低于 20% 时，其杀菌作用基本可以忽略不计。
16. Spirits labelled 95 proof contain only about 47 per cent alcohol.
- 句子类型
- 核心结构：主语 (Spirits) + 后置定语 (labelled 95 proof) + 谓语 (contain) + 宾语 (only about 47 per cent alcohol)
- 语法要点：① labelled 95 proof 为过去分词短语作后置定语，修饰 Spirits，表 “被标注为 95 标准酒精度的”，相当于定语从句 which are labelled 95 proof；② only about 为副词短语作状语，修饰宾语中的 47 per cent，表 “仅约”。
- 释义：标注为 95 标准酒精度的烈酒，其酒精含量仅约为 47%。
17. Beware of methylated alcohol, which is very poisonous and should never be added to drinking water.
- 句子类型
- 核心结构：祈使句 (Beware of methylated alcohol) + 非限制性定语从句 (which...)
- 语法要点：① 祈使句以动词原形 Beware 开头，Beware of 为固定搭配，表 “提防 / 小心”；② which 引导非限制性定语从句，指代前文的 methylated alcohol，which 在从句中作主语，从句用 and 连接两个并列的谓语（is/should never be added）；③ be added to 为固定搭配，表 “被加入…… 中”。
- 释义：要提防甲基化酒精，它有剧毒，绝不能掺入饮用水中。
18. If no other safe water supply can be obtained, tap water that is too hot to touch can be left to cool and is generally safe to drink.
- 句子类型：复合句（条件状语从句 + 定语从句 + 主句并列谓语）
- 核心结构：条件状语从句 (If...) + 主句 (tap water...can be left...and is generally safe...) + 定语从句 (that...)
- 语法要点：① If 引导条件状语从句，被动语态（can be obtained），表 “如果无法获得……”；② that 引导限制性定语从句，修饰先行词 tap water，that 在从句中作主语；③ 定语从句中含too...to... 结构，表 “太…… 而不能……”（too hot to touch：烫得无法触摸）；④ 主句中 and 连接两个并列的谓语（can be left to cool/is generally safe to drink），均为系表 / 被动结构，to cool/to drink 为不定式作补语。
- 释义：如果无法获得其他安全的饮用水，自来水龙头中流出的烫得无法触摸的水，放凉后饮用通常是安全的。
19. Those planning a trip to remote areas, or intending to live in countries where drinking water is not readily available, should know about the various possible methods for making water safe.
- 句子类型：复合句（分词作后置定语 + 定语从句 + 主句主谓宾）
- 核心结构：主语 (Those) + 多层后置定语 + 谓语 (should know about) + 宾语 (the various possible methods) + 后置定语 (for making water safe)
- 语法要点：① 主语 Those 后接两个并列的现在分词短语作后置定语：planning a trip to remote areas /intending to live in countries，表主动（“计划 / 打算” 的逻辑主语是 Those）；② where 引导限制性定语从句，修饰先行词 countries，where 在从句中作地点状语，从句为主系表结构（drinking water/is/not readily available）；③ readily available 为形容词短语作表语，表 “容易获得的”；④ for making water safe 为介词短语作后置定语，修饰 methods，表 “使水安全的方法”。
- 释义：那些计划前往偏远地区旅行，或打算在饮用水难以获得的国家生活的人，应该了解让饮用水变得安全的各种可行方法。
一、核心词汇
- contamination
- 搭配：contamination of water supplies 水源污染
- 拓展：contaminate v. 污染（动词原形，课文派生词）
- sanitation
- sewage
- 搭配：sewage disposal 污水排放；leakage of sewage 污水渗漏
- leakage
- distribution /ˌdɪstrɪˈbjuːʃn/n. 分配；输送；分布
- 搭配：distribution systems （水源）输送系统
- intermittent /ˌɪntəˈmɪtənt/adj. 间歇的；断断续续的
- 搭配：intermittent tap-water supplies 断断续续的自来水供应
- suspect /səˈspekt/adj. 可疑的；不可信的 ｜ /ˈsʌspekt/n. 嫌疑人（本课用形容词义）
- 搭配：be regarded as particularly suspect 被视为非常可疑
- untreated
- 搭配：untreated water 未经处理的水
- carbonated
- 搭配：carbonated drinks 碳酸饮料
- acidic
- rim
- 搭配：clean and dry rims 清洁干燥的瓶口
- portable
- 搭配：portable boiling elements 便携式加热装置
- voltage
- 搭配：the right voltage of electricity 适配的电压
- sterilize
- ethanol
- concentration
- 搭配：a concentration of 50-70 percent 50% 至 70% 的浓度
- bactericidal /bækˌtɪərɪˈsaɪdl/adj. 杀菌的
- 搭配：bactericidal action 杀菌作用
- negligible /ˈneɡlɪdʒəbl/adj. 微不足道的；可忽略的
- 搭配：negligible bactericidal action 几乎不存在的杀菌作用
- spirit /ˈspɪrɪt/n. 烈酒；精神（本课用 “烈酒” 义，可数复数）
- 搭配：spirits labelled 95 proof 标注 95 标准酒精度的烈酒
- methylated
- 搭配：methylated alcohol 甲基化酒精
- poisonous
- remote
- readily
- 搭配：not readily available 难以获得的
二、高频短语
- due to
- 例句：Contamination of water supplies is usually due to poor sanitation.
- be regarded as
- 同义：be considered as /be seen as
- 例句：Intermittent tap-water supplies should be regarded as particularly suspect.
- keep to
- 例句：It is best to keep to hot drinks, bottled or canned drinks of well-known brand names.
- on request
- 例句：Some hotels supply boiled water on request.
- in one's presence
- 例句：Make sure that all bottles are opened in your presence.
- rely upon/on
- 被动：be relied upon/on to do sth 被依靠做某事
- 例句：Alcohol should not be relied upon to sterilize water.
- at a concentration of
- 例句：Ethanol is more effective at a concentration of 50-70 percent.
- be added to 被加入…… 中（被动结构，主动：add...to... 把…… 加入……）
- 例句：Methylated alcohol should never be added to drinking water.
- too...to...
- 例句：tap water that is too hot to touch 烫得无法触摸的自来水
- leave to cool
- 例句：tap water that is too hot to touch can be left to cool.
- make sth safe
- 拓展：methods for making water safe 使水安全的方法
- be available
- 否定：not be readily available 难以获得的
- 例句：drinking water is not readily available 饮用水难以获得
- rather than 而不是（后接名词 / 动名词 / 不定式，表对比）
- 例句：Drinks can be cooled by placing them on ice rather than adding ice to them.
- know about
- 例句：You should know about the various possible methods for making water safe.
三、拓展高频搭配
- industrial or farm waste 工农业废弃物
- piped water supply 管道供水系统
- medical disinfectant 医用消毒剂
- international standard 国际标准
1. 被动语态 + 时间状语从句（表状态随过程变化）
原句：Even if a piped water supply is safe at its source, it is not always safe by the time it reaches the tap.套用结构：Even if ______ is ______ at its ______, it is not always ______ by the time it ______.适配场景：说明事物初始状态与最终状态的差异
2. 祈使句 + 并列宾语从句（表明确要求 / 注意事项）
原句：Make sure that all bottles are opened in your presence, and that their rims are clean and dry.套用结构：Make sure that ______ are ______ in your ______, and that their ______ are ______.适配场景：提出具体、双重的行为要求或检查标准
3. 主谓 + 方式状语（by doing）+ rather than（表选择取舍）
原句：Drinks can be cooled by placing them on ice rather than adding ice to them.套用结构：______ can be ______ by doing ______ rather than doing ______.适配场景：说明做某事的正确方式，对比排除错误方式
4. 情态动词表肯定 + 转折否定（表事物功能局限性）
原句：Alcohol may be a medical disinfectant, but should not be relied upon to sterilize water.套用结构：______ may be a ______, but should not be relied upon to ______.适配场景：说明事物的适用场景，指出其不可用于某类用途
5. 条件状语从句 + 定语从句 + 并列谓语（表特殊情况下的解决方案）
原句：If no other safe water supply can be obtained, tap water that is too hot to touch can be left to cool and is generally safe to drink.套用结构：If no other ______ can be ______, ______ that is ______ can be ______ and is generally ______ to ______.适配场景：给出无最优选择时，次选方案的使用条件与合理性
