我们知道定语从句最 好紧跟在修饰的名词后面，尽量不要被其他成分隔开，但是也会存在跳跃修饰的情况。
在前有“核心词+介词、分词等修饰结构”或者“插入语的情况下，which／that可以跳跃修饰前面的核心词，我们先来看几个例子吧：
1. Despite recent increases in sales and cash flow／ that have propelled automobile companies' common stocks to new highs, several industry analysts expect automakers, in order to conserve cash, to be more conservative than they have been／ in setting dividends.
解析：标红色的部分that 引导的定语从句，that是从句里面的主语，谓语动词是have， 说明that 代指的是复数名词，而离它最 近的是cash flow， 是不可数名词，不可能代指它，从句意上来说代指的是前面的increases，在这里就是跳跃了比较短的介词短语来修饰前面的名词
2. The use of lie detector is based on the assumption that lying produces emotional reactions in an individual that, in turn, create unconscious physiological responses.
解析：从句意上that 修饰reactions，在这里就是跳跃了短的介词短语
3. Changes in sea level result not only from changes in water temperature, which affect water density, but also from the melting of glaciers.
解析：通过affect来看，which指代的是changes，而不是temperature，在这里就是跳跃度短的介词短语in water temperature 修饰changes
4. From the bark of the paper birch tree the Menomini crafted a canoe about twenty feet long and two feet wide, with small ribs and rails of cedar雪松, which could carry four persons or eight hundred pounds of baggage yet was so light that a person could easily portage it around impeding rapids.
解析：这句话的which离其所应该修饰的核心词canoe很远，中间隔了一个插入语with small ribs and rails of cedar，还隔了个介词结构about…，但只要知道核心词是canoe就能一目了然找到which应该指的是什么，这里不能修饰紧邻的名词cedar
which／that 之所以要跳过介词结构是因为：其原本应该紧邻所修饰的核心名词，但是因为which的内容太长，而介词、分词等修饰结构又很短， 所以把which结构后置了。 但是要注意这种跳跃修饰是一种无奈之举，如果有选项能避免这种跳跃修饰，然后没有太大的语法问题，还是优先考虑没有跳跃修饰的选项哦 再补充定语从句中常见的两个知识点 1. 当先行词是介词宾语时，一般要将介词前置，形成介词+which结构 This is the factory in which his father works. 2. which不能代指前面的整句话，只能代指一个先行词，这个是错误选项经常出现的一个点，大家做题的时候一定要注意哦
