句子插入題是托福閱讀中的一道**題型，題量不多，每篇文章中出現一道。句子插入題是給出一句話讓我們來判斷這句話應該加入1-2個段落中的四個黑方塊的哪個部分，用鼠標點擊所選的黑色方塊即可。做這類題目的關鍵首先是理解待插入的句子，尋找其中的銜接詞，分析這個句子的特點和其在文中的作用，然后把這個句子帶入原文中檢驗其是否合適。下面朗閣海外考試研究中心的專家將就句子插入題的解題步驟做出詳細的說明。

一、解題步驟與解題要點

?  閱讀并分析待插入的句子，找出其中的線索詞；

?  從第一個小黑方塊前一句開始讀，逐一代入進行驗證；

?  插入句必須滿足前后兩條線索，先前再后。（先用前線索再看后線索）

從此步驟中可以看出掌握線索詞是解答此題的關鍵，那么線索詞都有哪些？主要有兩大類，指代線索和邏輯線索。

1.指代線索

(1). 指代詞(they,it, them)必然有所指代；指代詞(this, these, their,other, another, such)后面若有名詞短語，則向前尋找此名詞短語或其同義改寫。

例題1:

Paragraph 4: Regularly flowing rivers andstreams that originate within arid lands are known as "endogenous."These are generally fed by groundwater springs, and many issue from limestonemassifs, such as the Atlas Mountains in Morocco. Basaltic rocks also supportsprings, notably at the Jabal Al-Arab on the Jordan-Syria border. ■Endogenous rivers often do not reach the sea but draininto inland basins, where the water evaporates or is lost in the ground. ■Most desert streambeds are normally dry, but they occasionallyreceive large flows of water and sediment. ■

Paragraph 5: Deserts contain large amounts ofgroundwater when compared to the amounts they hold in surface stores such aslakes and rivers. ■But only a small fraction of groundwaterenters the hydrological cycle—feeding the flows of streams, maintaining lakelevels, and being recharged (or refilled) through surface flows and rainwater. (TPO16 Water in the Desert)

12. Look at the four squares [■] that indicate where the following sentencecould be added to the passage.

Thesesudden floods provide important water supplies but can also be highlydestructive.

Wherewould the sentence best fit?

解析：

1. 分析黑體句，找到其中的線索詞即為thesesudden floods, 則要插入的方塊前面必定要出現名詞短語suddenfloods或是其同義改寫。

2.從第一個小黑方塊前一句開始讀，尋找與線索詞相吻合的信息。

3.在第三個方塊前面出現了largeflows of water and sediment（巨大的水流和沉積物），即為suddenfloods的同義替換，所以答案應當是第三個黑方塊的位置。

例題2:

Paragraph 4: One of the outer planets, Saturn, has adensity of only 0.7 that of water, which means that Saturn would float inwater. Variations in the composition of the planets are largely responsible forthe density differences. ■The substances that make up both groups ofplanets are divided into three groups—gases, rocks, and ices—based on theirmelting points. ■The terrestrial planets are mostly rocks:dense rocky and metallic material, with minor amounts of gases. ■The Jovian planets, on the other hand, contain a largepercentage of the gases hydrogen and helium, with varying amounts of ices:mostly water, ammonia, and methane ices. ■ (TPO 16 Planets in Our Solar System)

12. Look at the four squares [■] that indicate where the following sentence could be added to thepassage.

Thisexplains their relatively low densities.

Where would the sentence best fit?

解析：首先分析待插入的句子，涉及兩個指代詞，this和their, 根據這兩個指代詞則能夠推出前文一定要講到某些密度較低的行星（即their所指代的），并且前面還要給出密度低的原因（即this所指代的）。然后閱讀段落，發現段落中首先提到行星構成成分的不同會導致密度的差異，然后講到類地行星(terrestrial planets)主要由密度大的石頭組成，然后提到類木行星(Jovian planets)是由大量的氣體組成的，所以正確答案應是第四個黑方塊的位置。

(2). 定冠詞the+名詞，用于重復上文提到的事物

例題1:

Paragraph 3: Film analysis of the infant'sresponses, heart and respiration rate monitors, and nonnutritive suckingdevices are used as effective tools in understanding infant perception. ■Film analysis permits researchers to carefullystudy the infant's responses over and over and in slow motion. ■Precise measurements can be made of the lengthand frequency of the infant's attention between two stimuli. ■Heart and respiration monitors provide theinvestigator with the number of heartbeats or breaths taken when a new stimulusis presented. ■Numericalincreases are used as quantifiable indicators of heightened interest in the newstimulus. Increases in nonnutritive sucking were first used as an assessment measureby researchers in 1969.

13. Look at the four squares [■] that indicate where the following sentencecould be added to the passage.

The repetition allows researchers to observe theinfant's behavior until they reach agreement about thepresenceand the degree of the infant's response.

Where would the sentencebest fit?

解析：分析黑體句，找到線索詞therepetition, 根據規則前文中應出現repetition這個信息，從第一個小黑方塊前一句開始分析，發現第二個黑方塊前面出現了…overand over and in slow motion, 識別出是repetition的同義改寫，則答案即為第二個小黑方塊位置。

例題2:

The universal global warming at the end of the Ice Age haddramatic effects on temperate regions of Asia, Europe, and North America. Icesheets retreated and sea levels rose. ■The climatic changes in southwestern Asia weremore subtle, in that they involved shifts in mountain snow lines, rainfallpatterns, and vegetation cover. ■However, these same cycles of change hadmomentous impacts on the sparse human populations of the region. ■At the end of the Ice Age, no more than a few thousandforagers lived along the eastern Mediterranean coast, in the Jordan andEuphrates valleys. Within 2,000 years, the human population of the regionnumbered in the tens of thousands, all as a result of village life and farming.■Thanks to new environmental and archaeologicaldiscoveries, we now know something about this remarkable change in local life.

13. Look at the four squares [■] that indicate where the following sentence can be added to the passage.

One of themajor effects was the rapid growth of the human population itself.

Where would the sentence best fit?

Click on a square [■] to insert the sentence in the passage.

解析：分析待插入的句子，可以找到線索詞the major effects, 則推出前文中一定要提到effects或其同義替換，本題中還有一個后線索，后面的句子中應該要提到人口的迅速增長這個信息。閱讀段落，發現these same cycles of change had momentousimpacts on the sparse human populations of the region中impacts即為effects的同義替換，并且第三個黑方塊后面的兩句話都在詳細論述人口從初的幾千人增加到上萬人，所以前后都符合線索詞，則正確答案為第三個黑方塊。

2.邏輯線索

在邏輯線索中主要會出現以下幾種情況：

(1). 插入句中出現表結果的表達：一般可以排除段首位置，注意因果的邏輯關系

表示因果關系的信號詞：therefore,thus, accordingly, consequently, hence, so, as a result等。

例題：

Paragraph 3: Another explanation for the focus on animalsmight be that these people sought to improve their luck at hunting. █Thistheory is suggested by evidence of chips in the painted figures, perhaps madeby spears thrown at the drawings. █But if improving their hunting luck was the chiefmotivation for the paintings, it is difficult to explain why only a few showsigns of having been speared. █Perhaps the paintings were inspired by the need toincrease the supply of animals. Cave art seems to have reached a peak towardthe end of the Upper Paleolithic period, when the herds of game weredecreasing. █ (TPO 4 Cave Art in Europe)

13. Lookat the four squares [█] that indicate where the following sentence could beadded to the passage.

Therefore, if the paintings were connected with hunting, some otherexplanation is needed.

Where would the sentence best fit?

解析：閱讀黑體句，發現了因果關系詞therefore, 從此句意思（因此，如果這些繪畫與狩獵有關，那么必定會有其他一些解釋）來看，待插入的位置前面應當出現thepaintings were connected with hunting這個信息，后面應當出現someother explanation。閱讀段落，發現在第三個方塊處信息有所轉變，其前面在講巖壁畫的主要動機是提高打獵*中率，后面在講巖壁畫或許是出于增加獵物的需求而畫的畫，所以跟前面的分析相吻合，答案即為第三個黑方塊。

(2). 插入句中出現表轉折的信號詞：插入的句子與前一句話的內容形成轉折關系。

標示詞：however,but, nevertheless, yet, on the other hand, rather than, instead of等

例題：

Paragraph 5: Children normally desire to vent aggressiveimpulses on other people, including their parents, because even the most attentiveparents cannot gratify all of their demands immediately. ■Yetchildren, also fearing their parents' punishment and the loss of parental love,come to repress most aggressive impulses. ■The Freudianperspective, in a sense: sees us as "steam engines." ■Byholding in rather than venting "steam," we set the stage for futureexplosions. ■Pent-up aggressive impulses demand outlets. They may beexpressed toward parents in indirect ways such as destroying furniture, or theymay be expressed toward strangers later in life. (OG Aggression)

11. Look at the four squares [■] that indicatewhere the following sentence can be added to the passage.

According to Freud, however, impulses that have been repressed continue toexist and demand expression.

Where would the sentence best fit?

解析：黑體句中出現了表轉折的邏輯關系詞however, 此句意思大意為“被壓抑的沖動會繼續存在并且要求表現出來”。閱讀段落，發現第二個黑方塊前面一句大意為“兒童由于害怕父母的懲罰和失去父母的愛通常會壓抑他們絕大多數的沖動”，看到這句話則可以發現其與待插入的句子句意有轉折關系，所以答案即為第二個黑方塊。

(3). 舉例關系

若出現forexample的舉例，則找其對應的分論點，插入句放在對應觀點之后。

例題1:

Paragraph 7:Although the ecosystem concept was very popular in the 1950s and 1960s, it isno longer the dominant paradigm. ■Gleason's arguments against climax and biome are largely valid againstecosystems as well. ■ Furthermore, thenumber of interactions is so great that they are difficult to analyze, evenwith the help of large computers. Finally, younger ecologists have foundecological problems involving behavior and life-history adaptations moreattractive than measuring physical constants. ■Nevertheless, one still speaks of the ecosystem when referring to a localassociation of animals and plants, usually without paying much attention to theenergy aspects. ■ (TPO 19 Succession,Climax, and Ecosystems)

13.Look at the four squares [■]that indicate where the following sentence could be added to the passage.

They may be moreinterested in researching, for example, the adaptations that some aquaticanimals undergo to survive in dry desert environments.

Wherewould the sentence best fit?

解析：黑體句中出現了for example, 則判斷出此句為一個舉例信息，則需要尋找其所對應的分論點，并且發現人稱代詞they, 說明前句中要提到一些人方可。閱讀段落后發現，第三個空格前出現了相關信息，youngerecologists have found…more attractive可對應信息theymay be more interested in researching …, 信息ecologicalproblems involving behavior and life-history adaptations是adaptations that some aquatic animalsundergo to survive in dry desert environments的上義信息，則可判斷出答案為第三個黑方塊。

例題2:

Paragraph 6:Second, primary groups are fundamental because they provide the settings inwhich we meet most of our personal needs. ■Withinthem, we experience companionship, love, security, and an overall sense ofwell-being. ■Not surprisingly,sociologists find that the strength of a group's primary ties has implicationsfor the group's functioning. ■Forexample, the stronger the primary group ties of a sports team playing together,the better their record is. ■

12. Look at thefour squares [■] that indicatewhere the following sentence could be added to the passage.

People who do not live alone, for example,tend to make healthier life choices and develop fewer pathologies than peoplewho live by themselves.

Where would thesentence best fit?

解析：分析待插入的句子，我們也看到了forexample, 則表明本句是一個舉例信息，我們同樣要找到其所對應的分論點，然后放在其分論點之后即可。尋找分論點則必須依賴于對句意的理解。待插入句意為“非獨居的人傾向于做出更健康的生活選擇，并且比起獨居的人有著更少的疾病”，我們可以看到本句所表述的大意即為非獨居的人會擁有的好處。閱讀段落，我們發現第二句話，大意為“在主要群體中，我們會感受到陪伴，愛，安全感還有一種整體的幸福感”，這句話寫出了在主要群體中生活的好處，可以充當我們舉例信息的論點，則答案即為第二個黑方塊。

(4). 并列關系

注意also,again等表示再一次的詞匯。

例題：

Less colorful birdsand animals that inhabit the rain forest tend to rely on forms of signalingother than the visual, particularly over long distances. ■The piercing cries of the rhinoceros hornbill characterize the Southeast Asianrain forest, as do the unmistakable calls of the gibbons. ■In densely wooded environments, sound is the best means of communication overdistance because in comparison with light, it travels with little impedimentfrom trees and other vegetation. ■In forests, visual signals can be seen only at short distances, where they arenot obstructed by trees. ■The male riflebird exploits both of these modes of signaling simultaneously inhis courtship display. (TPO 17 Animal Signals in the Rain Forest)

13. Look at thefour squares [■] that indicatewhere the following sentence could be added to the passage.

There is also the long, rather terrifyingcall of the male orangutan, which carries over considerable distances toadvertise his presence.

Where would thesentence best fit?

解析：分析待插入的句子發現句子中出現了also一詞，本句意為“這里也有紅毛猩猩的狹長的令人害怕的叫喊聲”，通過also一詞可以推斷出前文也應出現“叫喊聲”這一信息。閱讀段落，則發現第二句中寫到“犀鳥的刺耳的叫喊聲給東南亞的熱帶雨林賦予了特色，就像是長臂猿那明顯的叫喊聲一樣”，本句中提到了犀鳥和長臂猿的叫喊聲，所以應放在此句后面，第二個黑方塊即為正確答案。

以上即是對托福閱讀句子插入題的詳細分析，相信考生們掌握了以上的技巧和方法，對句子插入題能有更深入的了解，并且對于此類題目的解題方法也更加得心應手了。