Lesson 64 The Channel Tunnel海峡隧道 虚拟条件句 if条件状语从句

In 1858, a French engineer, Aime Thome de Gamond, arrived in England with a plan for a twenty-one-mile tunnel under the English Channel.

简单句因为介词短语(状语)变长

A engineer arrived in England In 1858. ^{在1858年一位工程师来到了英国。}

plan for + 名词/动名词 ^…的计划

• Little by little, he formulated his plan for escape.^{他一点一点地构想出了他的逃跑计划。}
• Is this your plan for making your way in the world ?^{这就是你要出人头地的计划吗？}

twenty-one-mile ^{加连字符，用单数，作定语}

• six-year-old
• my four-year-old daughter

He said that it would be possible to build a platform in the centre of the Channel.

This platform would serve as a port and a railway station.

serve as… = serve for… ^{起…作用，用作…，充当…}

• It will serve as a swimming pool.^{用作游泳池}
• This sofa can serve as/for (a) bed. ^{沙发当床用}

* The tunnel would be well-ventilated if tall chimneys were built above sea level. ^{真实条件句}

• If tall chimneys were built above sea level, ^{从句（假设过去）}the tunnel would be well-ventilated.^{主句（过去将来时）}
• If tall chimneys is built above sea level, ^{从句（假设现在）}the tunnel will be well-ventilated. ^{主句（一般将来时）}

In 1860, a better plan was put forward by an Englishman, William Low.

put forward (plan/suggestion) ^{提出（计划、建议等）}

• You know they wouldn’t accept your plan/proposal.
• Why did you put it forward?

* He suggested that a double railway-tunnel should be built.

表示“建议/命令/要求”的动词后 ^{宾语从句要虚拟(条件/语气)}

This would solve the problem of ventilation, for if a train entered this tunnel, it would draw in fresh air behind it.

认识条件句

• If a train entered this tunnel, it would draw in fresh air behind it. ^{真实条件句（有可能实现）}
• If a rocket were to enter this tunnel, it would draw in fresh air behind it. ^{虚拟条件句（不大可能实现）}
• If a rocket had entered this tunnel, it would have drawn in fresh air behind it. ^{虚拟条件句（过去与事实相反）}
• If a train enters this tunnel, it will draw in fresh air behind it. ^{主将从现(第一类：真实条件句)}
• If a train were to enter this tunnel, it would draw in fresh air behind it. ^{委婉假设或表达更低的可能性(第二类条件句)}
• If a train had entered this tunnel, it would draw in fresh air behind it now. ^{过去条件与现在结果混合(对现在的影响)}
• If a train enters this tunnel, it draws in fresh air behind it. ^{零条件句(表示普遍事实或科学规律)}
• If a train entered this tunnel, it might draw in fresh air behind it. ^{特殊条件句(表推测)}
• If by any chance a train were to enter this tunnel, it would draw in fresh air behind it. ^{强调假设（反事实假设的变化）}

the problem of ventilation ^{通风的问题}

If, at the time, the British had not feared invasion, it would have been completed.

虚拟语气(非真实条件句)中，与现在事实相反，从句用一般过去时；与过去事实相反，从句用过去完成时，此时主句格式为 would have done，would/could/should 都可以情态动词加 have done 表示对过去的推测，如 must have done，can't have done 等

if虚拟条件句“假设过去”

The world had to wait almost another 100 years for the Channel Tunnel.

第 3 类条件句是在 if 从句里设想纯粹想像的事情，在主句里讲述想像的结果，谈的是没有或永远不可能有的结果，指的是过去没有过的事情。

• If I had worked hard at school, I’d have got a better job. ^{if 从句用过去完成时，主句用 would have/ should have +过去分词}
• I’d have read that book if I could have bought it.^{在 if 从句中可用 could have +过去分词代替 had been able to +动词原形}

suggest/insist + that + 从句 ^{(特殊结构：should + do)用来表达建议或坚持的观点(正式语境或表达强调)}

• She suggested that he should arrive early for the meeting. ^{当suggest表建议的时候，从句用虚拟语气，后接动词是要用-ing 形式，后接 that 从句采用一种固定的用法“should+动词原形”（should 可省略）}
• He insisted that she should apologize for her behavior.
• The teacher suggested that the students should study harder for the exam.
• My parents insisted that I should go to college after high school.
• The doctor suggested that he should quit smoking for his health.

条件句是用来推测可能会发生什麽事丶可能发生了什麽事，以及我们希望会发生什麽事。在英语中，很多用到条件句的句子会包含「if」这个字。在英语中，有许多条件式的句子里会包含其中一种过去时的动词。此用法称为「过去非真实条件句」，因为即使我们用的是过去时，但实际上我们提到的事情根本没有发生过。构成条件句的方法主要有五种。在所有情况下，这些句子都是由一个「if 子句」和一个主要子句所组成。而在否定条件句中，有一种相当的句型结构——以「unless 条件句」来取代「if 条件句」。

零条件句

零条件句是用在论及现在或任何时候的情况，而且是真实丶有可能发生的。零条件句一律用在论及真理上。句中两个部分的时态都是用一般现在时。在零条件句中，「if」一般可以用「when」来代替，并不会改变意思。

第一类条件句

第一类条件句用来指现在或将来的真实情况。第一类条件句指的是可能的情况，以及该情况可能造成的结果。在这些句子中，if 子句的时态要使用一般现在时，而主要子句是一般将来时。

第二类条件句

第二类条件句指的是现在或任何时候，而且情况与事实相反。这些句子并非根据事实，第二类条件句用来指一个假设情况，以及该情况可能造成的结果。在第二类条件句中，if 子句用的时态是一般过去时，而主要子句用的是条件式现在时。

第三类条件句

第三类条件句用来谈论过去与事实相反的情况。这些假设情况根据的事实是句中所表达的反面。第三类条件句用来论及过去不真实的情况，以及该情况在过去可能造成的结果。在第三类条件句中，if 子句用的时态是过去完成时，而主要子句使用的是条件式完成时。

混合型条件句

混合型条件句指的是过去，而且某个情况持续到现在。这些假设情况根据的事实是句中所表达的反面。混合型条件句是用来论及过去不真实的情况，以及该情况在现在可能会有的结果。在混合型条件句中，if 子句使用的时态是过去完成时，而主要子句用的是条件式现在时。