許多考生在進行託福聽力備考的過程中經常會有一種感覺就是學術講座(lecture)的信息量較多，無法完全在短短的2-3分鐘時間內記錄下所需要的關鍵線索。
阿倫老師對託福聽力高分同學們做了一次學習習慣調查，發現高分同學普遍在聽力中對各類提示的關鍵信息的信號詞有充分的了解和敏感度，而低分同學通常在這一塊相對比較缺乏。
今天阿倫老師就來為大家詳細解讀託福聽力備考中學生們需要予以關注的三大關鍵信號詞。
1
解釋說明類(Explanatory)信號詞
解釋說明類(Explanatory)信號詞
常見的有同意替換和舉例說明。同義替換，常見的信號詞有
that is；
namely；
or rather；
to be more exact；
to put it another way；
in other words;
by definition;
在託福聽力中，我們經常會聽到進行定義介紹的說法如「it is called + 專有名詞」，或者「專有名詞 refer(s) to …」。一般而言，這類專有名詞術語某個特定的領域，如商業、教育學、考古學、地球科學。考生相對不太熟悉，因此這些信號詞的前後內容能夠增加考生對整體聽力講座的把握和主旨理解。
TPO 33 The Great Pyramid
The Great Pyramid of Giza in Egypt might be the most famous building in the world. We know exactly when it was built. Construction started in 2547 B.C.E., about 4500 years ago. We know who had it built.That was the pharaoh Khufu. We know who oversaw its construction—the pharaoh’s brother. We know so many things about it, but the funny thing is: we still don’t know exactly how it was built.
TPO 49 Montessori Method
Professor: Ok, if you did your reading for today, then you were introduced to a very influential alternative to traditional education. This educational philosophy and methodology was pioneered in Italy in the early 1900s by Doctor Maria Montessori.It's called the Montessori Method.But what made the Montessori Method for young children so different? What made it so different, so special?
TPO 26 Green Marketing
Professor: Last class someone asked about green marketing.Green marketing refers to companies promoting the products as environmentally friendly.Companies often turn to advertising experts to help them do this.
託福聽力中，教授也常會進行舉例說明。常見的舉例信號詞：
for example；
just as；
for instance,
通過舉一些常見或者比較容易理解的例子，去解釋某樣事物或某個現象，使得其更加生動形象，通俗易懂。
TPO 42 Service Recovery
Professor: Oh, there are literally hundreds of examples. Service providers must of course constantly strive to meet customers』 needs. But, as in retail,their instances of service failure in whichthe customers dissatisfied, perhaps to the point not doing business with you anymore. Some service failures are beyond our organization and control,likecomputer mail function that leads to miss-deadlines.
這篇商業題材的講座中，教授在開篇簡單列舉了服務行業(service providers)中幾種失敗案例(service failure)，比如miss deadlines, process problems, human error, 並且根據原文So, if you are in a service industry, as a marketer you always need some kind of service recovery plan.可知她此次lecture的目的就是為了強調這些關於服務行業失敗案例對應方案的重要性。這一部分配合原題的中的內容主旨題，考生們可以迅速掌握文章的主旨信息。
細節信息類信號詞
還有一大類也是高頻出現的細節信息，就是數字、時間和人名地名這類信號詞。但是尤其需要注意，不能光聽數字和時間，更多的是要注意數字或時間背後所對應的內容和發生的事件，這在託福聽力歷史類篇章中，時間信號詞對於整篇文章的時間邏輯順序發展就顯得格外重要。人名和地名也是一樣，要注意該人物的特點或經歷，該地點發生的事件。
TPO 6 Boom and Burst
Professor: Now when I mention the terms "boom and bust", what is that going to mind?
Student: The dotcom crash of the '90s.
Professor: Ok. The boom in the late 1990s when all those new Internet companies sprung up and then sold for huge amounts of money, then the bust around 2000…2001 when many of those same Internet companies went out of business.
從教授說人們應該從過去吸取教訓得知，教授認為人們應該從所總結的規律中推測出或意識到 dot-com crash 是很有可能發生的。因此是she thinks that people should have realized it would happen
以上就是託福聽力中的3大類關鍵信號詞介紹，希望能夠為大家提供一些參考幫助。
2
邏輯性(Logic)信號詞
邏輯性信號詞
如最常見的原因、對比、轉折、並列等。
對於原因信號詞，考生可以尤為注意
because (of);
so;
the reason why;
since;
as/for;
等類型的詞或詞組，考生在聽到這些信號詞的時候一定要注意聽後面的解釋，通過現象或定義看到問題的本質和根源，這才是考核的關鍵所在。
TPO 42 Service Recovery
But your customer is less concerned about this source of the failure than the solution. What you do about it? What sort of compensation, what service recovery you give?So,if you’re in the service industry, as a marketer, you always need some kind of service recovery plan. Your plan must in place before failure occurs, and it must also be communicated promptly to everyone in your organization who deals with customers,sothey will know what to do.
此處教授用汽車租賃中介(Car Rental Agency)作為例子，舉例說明比如顧客進行預約但是員工卻記錯了日期，此時應該如何對顧客進行一些補償(sort of compensation)，這就是服務補救(service recovery)。教授借這個例子來介紹服務補救規劃(service recovery plan)的這個概念。
對於對比信號詞，考生除了注意比較級和最高級之外，還要多注意
compare to;
different from……l
unlike……;
(not) as ……as;
等這些間接表達對比的詞或詞組。
TPO 15 Distraction
Professor：
Yes, and that's one of the hypotheses that was proposed, that the brain simply doesn't admit the unimportant information.
That was quite a surprise and it proved that the second hypothesis – that we do perceive everything all the time but the brain categorizes distractions differently, well, that wasn't true either.
此處，研究者們做出了認知失敗問卷(CFQ), 從中研究者們提出了兩個研究假設：
第一個是大腦是否不會接受非重要信息(unimportant information)；
第二個假設是大腦會對認知的處理有所不同。這一部分是間接對比；
而考生更多是要找到相同的聯繫點(similarities)或者是在相似的事物中找到差異點(differences)。
轉折信號詞是TPO中最常見的信號詞之一。常見的信號詞形式如下：
however；
nevertheless；
yet；
still；
though；
anyhow；
even so；
in any case；
anyway；
after all；
in spite of that；
by the way；
這些是考生尤其應該注意的信號詞。即教授最終想要強調的點，也是高頻考點的地方。通過先陳述一部分事實或者拋出一個問題，然後來一個轉折性的連詞，提出真正的觀點。因此這些轉折詞前後信息是考生必須要注意的地方。
TPO 49 Pottery
The form of a pot can give us same ideas about its function, the suitability of the pottery to serve a specific function. However, we have to be careful when it comes to skeuomorphs. These objects are copies of the designs of other objects, but in another material. And this can be problematic, because sometimes the new or different material is not well suited to the design.
對於並列信號詞，
first；
second；
third；
for a start；
for one thing；
for another；
to begin with；
next；
則是很好的信號詞，提示了兩句句子之間的平等並列關係。
TPO 47 John Cage’s Music
Two experiences in particular entirely changed how he thought about music.
The first washis 1951 meeting with the avant-garde painter Robert Rauschenberg …
The second key experience in Cage’s development camewhen he stepped into an anechoic chamber.
這篇講座的主旨，就是一群叫做avant-garde的音樂家，其中一個典型就是作曲家Cage. 結合後文，我們知道這整篇講座都在講這個Cage創作了一首全是無意收錄的聲音的曲子。 這裡說到啟發Cage的兩件事，第一件是1951年他的一次會談；第二個事件，就是絕對靜音的一間屋。Cage在裡面聽到了自己的神經系統和血液循環的聲音。
3
細節信息類(detailed)信號詞
細節信息類(detailed)信號詞
還有一大類也是高頻出現的細節信息，就是數字、時間和人名地名這類信號詞。但是尤其需要注意，不能光聽數字和時間，更多的是要注意數字或時間背後所對應的內容和發生的事件，這在託福聽力歷史類篇章中，時間信號詞對於整篇文章的時間邏輯順序發展就顯得格外重要。人名和地名也是一樣，要注意該人物的特點或經歷，該地點發生的事件。
TPO 6 Boom and Burst
Professor: Now when I mention the terms"boom and bust", what is that going to mind?
Student: Thedotcom crash of the '90s.
Professor: Ok. Theboom in the late 1990swhen all those new Internet companies sprung up and then sold for huge amounts of money,then the bust around 2000…2001 when many of thosesame Internet companies went out of business.
從教授說人們應該從過去吸取教訓得知，教授認為人們應該從所總結的規律中推測出或意識到 dot-com crash 是很有可能發生的。因此是she thinks that people should have realized it would happen
以上就是託福聽力中的3大類關鍵信號詞介紹。