考过托福考试的考生应该都知道，托福听力材料分对话和讲座两类，主要以传统四选一的选择题为主，采用三种方式考查考生对听力材料的基本理解：内容主旨题、目的主旨题和细节题。只有分清楚了题目要问我什么，考生才能知道需要留意听什么、记笔记时重点记什么、分析选项时才知道排除哪些选项。
托福听力中，主旨题是出现频率非常高的题目了。相信备考听力的同学们不会对主旨题感到陌生，且会积累到主旨题的一般规律以及解题技巧。对于一部分同学而言，在听Lecture开头的部分的时候，会先泛听课堂回顾的内容，然后等待Today, let’s focus on…此类的提示词，进而捕捉主旨。但同学们需注意，并非每篇文章都会符合一般规律，甚至有的文章会设置一些陷阱，接下来我们就来学习一些技巧，避免主旨题“踩坑”。
01
从第一句开始集中注意力
听力文章毕竟是直接取自北美的真实课堂场景，难免会有老师会以不同的方式来开始自己的教学，开门见山的方式其实就是陷阱的来源之一。有的同学习惯了前面内容泛听，逐渐进入状态，就会导致错过主旨关键信息。
例如：Ok, back in the 1930s, a biologist named G.F.Gause first proposed what’s known as “Gause’s hypothesis”. Gause said that whenever youve got two similar species competing for the exact same limited resources, one of them will have some sort of advantage,however slight thatll eventually enable this species to dominate and ultimately exclude the other one, even cause it to become extinct. Thats why Gauses hypothesis came to be called "The competitive exclusion principle". (TPO36 Lecture 4)
02
区分小故事和主旨
教授为了在课堂开始时吸引学生的注意力，会以一些小故事或者例子来开始整个课堂，在讲完故事或例子之后才会出现主旨，会有学生把这些小故事或者例子当成主旨。
如TPO54的这篇：A popular misconception about archaeology: Some people imagine we just go out into the field with a shovel and start digging,hoping to find something significant.
Well, while there is an element of luck involved, we have an array of high-tech tools to help us figure out where to concentrate our efforts.
One of the newer tools actually relies on particle physics. Talk about interdisciplinary!
Heres a machine that brings together two very different sciences.This machine is called a muon detector. (TPO54 Lecture 2)
有的同学听到第一句的misconception就赶快记下来了，主旨题就选择了misconception相关选项。但其实这个词其实是professor来吸引学生们注意，进一步引入muon detector这个重点信息的。
03
识别背景介绍
Professor为了让学生更好地理解课上讲解的重点，会在开头部分进行背景介绍。
如：We’ve been talking about animal cognition - the study of animal intelligence. Now, much of the research in this area is motivated by the search for animal analogues, or parallels to human cognitive processes. And one of the processes we’ve been investigating is metacognition. (TPO30 L1)
有的同学听到第一句对animal cognition进行下定义，会误以为主旨与此相关。其实对animal cognition的讲解是为了引出metacognition这个重点。
