都说托福阅读部分文章有难度，其实这种难度很多时候来自于文章中的长难句。这些句子结构复杂内容繁多，考生如果无法快速正确地看懂它们必然会影响对文章的理解和解题效率。所以下面小编就为大家带来托福阅读100个长难句的精选汇总和深度解析，为大家提供学习指点和启发。

托福阅读100个长难句实例分析

原句案例：

Geographic isolation creates opportunities for new species to develop, but it does not necessarily lead to new species because speciation occurs only when the gene pool undergoes enough changes to establish reproductive barriers between the isolated population and its parent population.

词汇解释：

isolation: one group, person, or thing is separate from others.

speciation: speciation is the evolutionary process by which new biological species arise.

gene pool: the gene pool is the set of all genes, or genetic information, in any population, usually of a particular species.

结构分析：

并列复合句

句1 Geographic isolation creates opportunities for new species to develop，

句2 but it does not necessarily lead to new species because speciation occurs only when the gene pool undergoes enough changes to establish reproductive barriers between the isolated population and its parent population.

*其中句2含有because引导的原因状从和when引导的时间状从。

句子分析：

句1中

geograhic isolation 主语， creates 谓语，opportunities 宾语， for new species 介词结构作定语，to develop, 目的状语。本部分意思：地理隔离创造了新物种发展的机会。

句子2

主句部分 ：but it does not necessarily lead to new species

it 主语，指代geographic isolation， does not necessarily lead：谓语部分， to new species：宾语。本部分意思：但它不一定会导致新物种

原因状语从句：because speciation occurs

speciation是主语，occurs 谓语。

本部分意思：因为新物种的出现(产生)。

时间状语从句：when the gene pool undergoes enough changes to establish reproductive barriers between the isolated population and its parent population.

the gene pool，主语;undergoes，作谓语;enough changes 宾语。

to establish 状语。其中，reproductive barriers是establish的宾语。

between the isolated population and its parent population,介词结构作定语，说明是isolated population 和 its population之间的障碍。

本部分意思：因为只有当基因库产生足够的变化，使得分割种群与其总群之间产生繁殖障碍时。

参考翻译：

地理隔离创造了新物种发展的机会，但它不一定会导致新物种，因为只有当基因库产生足够的变化，使得分割种群与其总群之间产生繁殖障碍时才会产生新的物种。

托福阅读中的长难句虽然会对考生造成一定的干扰，但只要考生具备了快速看懂理解它们的能力，其实长难句也并非难以应对，希望本文内容能够帮助大家提升阅读实力拿到高分好成绩。