托福听力部分包括十三大听力原则，主要是根据听力的内容以及文章构架的布局。十三大听力原则能够帮助考生更快地定位听力要点，从而在短时间内，快速定位答案。

第一部分：托福考试听力开头方式

    托福听力包括对话和讲座两部分内容，对于对话和讲座的开头方式并不相同，下面分别介绍一下托福听力开头部分的方式。

1、对话：学生和老师或者是工作人员的先后顺序

1)学生先开口说：学生先开口，就会陈述问题的内容，直接进入主题;

2)学生未开口，老师先说一件事或一个问题;

3)学生来交一个材料，老师提出另外的一些问题;

4)学生和老师用了很短时间解决了一个学生问题，学生又问了另外的问题。

2、讲座：主要是教授或者老师针对一个话题展开讨论

1)课堂回顾式

2)直入主题式

3)背景引入式

4)寒暄离题式

第二部分：听力讲座四种开头方式

1)课堂回顾

TPO1-L3

    OK,we've been talking about early agriculture in the near east. So let's concentrate on one site and see what we can learn from it.

     OK.In the last class, we started talking about useful plant fibers...Today well continue talking about useful fibers, and we'll begin with a fiber that's commonly known as "Manila hemp."

    大家可以注意到加粗部分的内容，是针对课程或者课堂内容的回顾。课堂回顾是我们听重点的一个提示而已，我们要关注的是后边的内容，也就是“本堂课”要注意的内容。

课堂回顾式常见关键点：

时态：一般过上时或者是现在完成时、现在完成进行时

关键词：in the last class, today, now, talk about, but.

2)直入主题式

TPO18-L1

OK,today we are going to start a study of sunspot today

Ok,now I want to talk about an animal that has a fascinating set of defense mechanisms.

直入主题的开头方式，需要考生集中精力听讲座的内容，不要错过听力的有效信息。

直入主题式常见关键点：

时态：一般现在时或者将来时

直入主题式常见关键词：now, want to talk about,

3)背景引入式

OG-test 2-L4

We've been looking at colossal statues—works of exceptionally huge size—and their essentially public role, in commemorating a political or religious figure. How some of these statues date back thousands of years... like the statues of the Pharaohs of ancient Egypt—which you can still visit today... and how others, though surviving only in legend, have fired the imagination of writers and artists right up to our own time, such as the Colossus of Rhodes, that 110-foot statue of the Greek god Helios. Remember, this same word, "colossus”一 which means a giant or larger-than-life-size statue—is what today’s term "colossal” derives from. Now, it was one thing to build such statues, at an equally colossal cost, when the funds were being allocated by ancient kings and pharaohs. But if we're going to think about modern-day colossal statues, we need to reexamine more closely their role as social and political symbols—in order to understand why a society today—a society of free, tax-paying citizens—would agree to allocate so much of its resources to erecting them.

   背景引入式的开头方式，是听力讲座，尤其是学术类讲座的一个重要特点。为了引出讲座的主题，教授会在一开始的时候，先将一下相关的背景，循序渐进地带入。

背景引入式常见关键点：

时态：一般现在时或者过去式

4)寒暄离题式

TPO2-Lecture2

     Hi,everyone. Good to see you all today. Actually, I expected the population to be a lot lower today. It typically runs between 50 and 60 percent on the day the research paper is due. Um, I was hoping to have your exams back today, but, uh, the situation was that I went away for the weekend, and I was supposed to get in yesterday at five, and I expected to fully complete all the exams by midnight or so, which is the time that I usually go to bed, but my flight was delayed, and I ended up not getting in until one o'clock in the morning. Anyway, I," do my best to hove them finished by the next time we meet.

    寒暄离题式的开头方式比较符合中国的传统文化，先是客套一番，然后才进入课程的主要内容或者是表达作者的观点。在遇到这类问题的时候，一定要注意分别是寒暄部分，还是课程的内容部分。