2022年12月英语六级第1套真题句子解析： These included measures to reduce air pollution; to control the damage to marine ecosystems, which can have a huge effect on fish stocks on which hundreds of millions of people depend; and to curb the degradation of land where modern agricultural methods were pursued without regard to the longer-term consequences.

to reduce air pollution; to control the damage to marine ecosystems, which can have a huge effect on fish stocks on which hundreds of millions of people depend; and to curb the degradation of land

三个不定式短语通过分号和"and"连接，构成并列结构。第一、二项由分号连接，第二、三项由"and"连接。这三个不定式短语在句法层级上对等，共同作为"measures"的后置定语，列举了三类不同的措施。

to reduce air pollution

不定式短语"to reduce air pollution"修饰前面的名词"measures"，说明措施的具体内容和目的。不定式作后置定语是名词修饰的常见方式，此处与其他两个不定式短语（to control... 和 to curb...）并列，共同修饰measures。

to control the damage to marine ecosystems

不定式短语"to control the damage to marine ecosystems"与前面的"to reduce air pollution"并列，同样作为"measures"的后置定语，说明措施的另一项内容。

to control the damage to marine ecosystems, which can have a huge effect on fish stocks on which hundreds of millions of people depend

第一层是"which can have a huge effect on fish stocks"作为非限定性定语从句修饰"marine ecosystems"；第二层是"on which hundreds of millions of people depend"作为限定性定语从句嵌套在第一层从句内部，修饰"fish stocks"。形成了定语从句套定语从句的两层嵌套结构。

to curb the degradation of land

不定式短语"to curb the degradation of land"是第三个并列的不定式短语，继续作为"measures"的后置定语，说明措施的第三项内容。

to curb the degradation of land where modern agricultural methods were pursued without regard to the longer-term consequences

第一层是"where modern agricultural methods were pursued without regard to the longer-term consequences"作为定语从句修饰"land"；第二层是在该定语从句内部嵌套了过去分词"pursued"的后置定语结构。形成了从句套非谓语的嵌套。

pursued

过去分词"pursued"作为后置定语修饰"modern agricultural methods"，表示被动关系，即"被采用的现代农业方法"。这里过去分词引出的定语从句省略了关系代词which/that和be动词，完整形式应为"which were pursued"。

have a huge effect on

"have an effect on" 是典型的轻动词结构，"have" 本身语义较虚，重心在抽象名词 "effect"（影响）上，"on" 引出影响的对象。这里 "effect" 被形容词 "huge" 修饰，但核心搭配 "have effect on" 保持完整。

识别要点：① "have" + 抽象名词（如 impact/effect/influence）；② 名词后接固定介词 "on"；③ 整体表达「对...产生影响」的含义。注意与实义动词 "have"（拥有）区分，本结构中 "have" 是轻动词，语义重心在 "effect" 而非 "have" 本身。

常见变体："have an impact on", "have an influence on", "have a bearing on" 等，核心框架相同，都是 "have + 影响类名词 + on"。名词前可加形容词修饰（如 huge, significant, positive, negative），但不影响固定搭配的识别。

迁移方法：遇到 "have" + 抽象名词结构时，判断 "have" 是否为轻动词（语义虚化），以及名词后是否有固定介词搭配，从而识别此类固定框架。

on which hundreds of millions of people depend

介词前置定语从句的核心是「介词 + which」整体前移到关系代词位置，引导定语从句修饰先行词。这里 "fish stocks" 是先行词，"on which" 引导定语从句，"which" 指代 "fish stocks"，介词 "on" 与从句内动词 "depend" 构成固定搭配 "depend on"（依赖于）。

识别方法：① 找到「介词 + which」结构；② 确认 which 指代前面的名词（先行词）；③ 验证介词是否与从句内部动词/形容词构成固定搭配或逻辑关系。本句中 "depend on fish stocks"（依赖鱼类资源）的逻辑关系清晰，介词 "on" 被前置到 "which" 之前。

还原理解：可将从句还原为 "hundreds of millions of people depend on fish stocks"，然后将 "fish stocks" 替换为 "which"，介词 "on" 前置，形成 "on which hundreds of millions of people depend"。这种结构在正式书面语中更常见，口语中更倾向于 "fish stocks which/that hundreds of millions of people depend on" 或省略关系代词。