1 If Confucious should have seen her doing that, he would certainly have struck her shins with a stick.

这个句子显然是虚拟语气，if从句是与事实相反的假设。语法书讲虚拟语气，告诉你一个动词的使用原则，并不是说与过去事实相反就一定要用had done, 用情态动词过去形式+have done也可以表示与过去事实相反。should do可以表示与现在或将来时事实相反（或不大可能在将来实现的条件），should have done在表示在过去不大可能是事实。

2 是的，that引导定语从句，先行词为what programs。

3 理解这个句子，你先要理解习语 go to any length or go to any/extreme/great (etc.) lengths

: to make a great or extreme effort to do something

• He went to great lengths to learn the truth.

But the surfeit of counterfeit calls主语 underscores谓语动词 the lengths宾语 （to which状语 people主语 feel系词 compelled to go to project an image for others过去分词短语作表语.)

其中，to which为to go的状语，to protect...为to go的目的状语。to go...为compelled的补足语。

4 What a mystery lies in doors！

这是感叹句。感叹句中，感叹短语可以是表语，也可以是状语、宾语、主语。本句中感叹短语作主语。划线部分为感叹短语。

What a mystery lies in doors！感叹短语作主语

What a clever boy he is ! 感叹短语作表语

What an interesting book he wrote! 感叹短语作宾语

How fast he runs! 感叹短语作状语