托福聽力雖然涉及到的話題種類很多，但其中也有較為明顯的出現頻率差異，比如歷史類話題，在講座類lecture中就屬于相當高頻的一類話題。而這類話題由于內容較為冷僻，很多同學其實都比較缺乏了解。那么面對此類話題考生如何才能抓住關鍵信息進行解題呢?下面小編就為大家介紹5個關鍵要素。

托福聽力歷史類話題關鍵要素一：主題關鍵詞

托福聽力講座類lecture歷史類話題總是會出現和發展、起源或者歷史相關的詞匯，比如develpoment, change, origin, historical等等，這些詞匯有很明顯的提示作用，大家需要留意，比如：

Professor: And what instrument comes to mind when you think of rock ‘n' roll?

Student: The electric Guitar?

Professor: Exactly. I think it's fair to say that the sound of the electric guitar typifies the rock ‘n’ roll genre,which became popular in the 1950s. But really the instrument we know today was the result of a continuing development that started for our practical purposes in the 1920s. But long before that even,people were experimenting with ways to modify traditional acoustic guitars.

大家需要注意到文章開頭做了兩件事情：一. 提出話題“ Electrical Guitar”; 二. 提出了歷史類文章要素, 教授說到電吉他是一個“the result of a continuing development” 而且人們很早之前就開始“ modify acoustic guitar”，自然而然我們就能推測文章是要講電吉他是如何發展起來的。

托福聽力歷史類話題關鍵要素二：影響

具體來說，影響包括了話題的發展;發展過程中所受到的影響;其所產生的影響;具體的影響是什么;怎么影響的等等，比如：

The first guitars were wooden. This is the Spanish guitar and the strings were made from animal products. Then came steel strings. And that led to the lap guitar,which is also called the steel guitar because the player slides a steel rod up and down the neck. And those are all acoustic guitars. OK?

But then eventually we have electric guitars. Over the years,many inventors and musicians contributed to the design of these instruments. And each design was intended to alter the sound in some way,at first at least with the electric guitar,to make it louder.

很明顯的，教授接下來就開始講到吉他的發展過程，第一種吉他，wooden aka spanish guitar;接著steel guitar;lap guitar;然后有了electric guitar。而且重點說到“ 很多的發明者和音樂家對這種樂器的設計做出了貢獻，而且每次的修改的目的就是為了改變電吉他的聲音，也就是要素中提到的對話題的影響。

隨后，教授繼續細致的按照一定的順序談到了人們對于電吉他的修改有哪些方面，

托福聽力歷史類話題關鍵要素三：時間

時間順序也是關鍵要素。當然，大家可能會注意到，下面例子提到的具體的時間點貌似只有兩個1890s 和1920s。但是總的來講，歷史類的文章，時間順序是一件非常關鍵的事情，因為在講到某個事物的發展總是會從前往后說，提醒一點的是，時間本身不重要，只要搞明白誰前誰后即可。具體例子如下：

So let's get back to when the steel guitar was first introduced in the United States. It was right after the Spanish-American war in the late 1890s. US sailors who were stationed in Hawaii—then a US territory—were very enamored with the music they heard there. Uh,Hawaiian music was based on the steel guitar I just described. Some sailors learned how to play the steel guitar and brought it home to the States. Before long,Hawaiian steel guitar music was all the rage in the mainland US. It actually had a strong influence on the development of several musical genres,rock ‘n' roll most notably,but also jazz and blues.

Anyway,by the 1920s,with the advent of the public dance movement,people were gathering in large groups to listen to steel guitar music. But they had trouble hearing it,especially in large public settings. As I mentioned,the instrument was played horizontally,on the lap. Since the strings faced upward,the sound was projected toward the ceiling rather than outward toward the audience. Something had to be done,because the music venues and the audience kept getting larger and larger.

托福聽力歷史類話題關鍵要素四五：話題的特點&人物

一般這兩點都是融合在一起的，例子：

Electrified guitars already existed by the time Les Paul came into the picture around 1940. What Paul did was experiment with ways of removing the distortions and he succeeded. He designed a guitar with a solid body that relied solely on electronics. Paul's solid body eliminated the vibrations,and thus the distortions.

此處教授講到Les Paul此人對于電吉他的修改，使得電吉他有了一個”solid body” ， 減少了聲音失真的狀況。大家尤其要注意，如果一篇文章出現了好幾個人和一個事物的好幾個特點的時候，一定要警覺起來，區分清楚哪個特點，屬于哪個人物，這通常都是要出難題的前兆。

以上就是托福聽力講座類lecture中高頻話題歷史類的5個關鍵信息要素，希望大家能夠有所了解并抓住核心信息。