句子插入题，也叫插入文本题。就是将一个新句子插入到原文合适的地方——这个地方缺了一个句子。做题时必须理解原文的逻辑和句子之间的语法关系（如代词的指代）。原文有四个黑方块[■]，这些方块位于句子的开头或结尾。它们有时出现在同一个段落中，有时出现在两个段落中。

问题的形式是：

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

[You will see a sentence in bold.]

Where would the sentence best fit?

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

做题步骤：

1）看选项，抓线索

先仔细阅读待插入的句子，弄清其含义，找出其中包含的衔接手段，根据词汇、逻辑、语法等衔接手段先对待插入句可能的前后句内容先做出适当预判。

2）观前后，找特征

看四个方块前后的句子，寻找其中的核心词，即如上述与待插入句子中的衔接手段相匹配的线索。

3）插句子，定答案

将句子插入到确定的位置，然后阅读上下句与插入句，从逻辑和语义上判断它和上下句之间是否连贯。

做题思路：

根据词汇、逻辑、语法等衔接手段可总结出四种最常见的做题思路，分别为：重复暗示、指代暗示、概述暗示和逻辑暗示。

即：拿到被插入句，先找出句中信息点所给的暗示，通常我们能找出上述四种中的至少一种暗示，然后根据这一种或多种暗示，判断前后句是否在逻辑和语义上都衔接恰当，选出答案。

我们来看几个例题，看如何就被插入句信息点找到暗示，完成衔接：

例1

Scientists have known for some time that certain plants, called hyperaccumulators,can concentrate minerals at levels a hundredfold or greater than normal. ■A survey of known hyperaccumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of choice. ■Hyperaccumulators run the entire range of the plant world. ■They may be herbs, shrubs, or trees. ■Many members of the mustard family, spurge family, legume family, and grass family are top hyperaccumulators. Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial pathogens.

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

Certain minerals are more likely to be accumulated in large quantities than others.

Where could the sentence best fit?

先阅读待插入句，我们能找出minerals这个核心概念，利用这个概念的重复暗示，可先排除C和D选项，因为C、D方框前后都在围绕Hyperaccumulators run the entire range of the plant world句进行展开，不再涉及minerals相关信息。而A、B方框周边都有提到minerals这一信息，可判断不是A就是B。再根据待插入句本身的表述certain minerals...（某些矿物质更有可能……）判断这是一个概述暗示，后面一般会对这个概述句的内容进行细节展开，这和B方框后句子内容吻合，这是对待插入句的解释说明，所以可判断选A不选B。

例2

One interpretation regarding the absence of fossils during this important 100-million-year period is that early animals were soft bodied and simply did not fossilize. ■Fossilization of soft-bodied animals is less likely than fossilization of hard-bodied animals, but it does occur. ■Conditions that promote fossilization of soft-bodied animals include very rapid covering by sediments that create an environment that discourages decomposition. ■In fact, fossil beds containing soft-bodied animals have been known for many years. ■

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

It is relatively rare because the fossilization of soft-bodied animals requires a special environment.

Where could the sentence best fit?

先阅读待插入句，句子开头即为一个指示代词it，即指代暗示。据此我们将此句插在任一方框，方框的前句应有这里it所指代的内容，并在语义和语法上都衔接通畅。另外待插入句后半句提到...requires a special environment，这也是一个概述暗示，紧接着一般会对这个special environment进行细节展开描述。据此，我们可以预判待插入句前面应描述到it所指代的内容并且它是相对稀少的（根据it is relatively rare），后面应该会描述到特殊的环境（special environment）具体是一个什么样的环境。接着来看每个方框前后句子的核心信息，判断应该选B。B的前句提到软体动物的化石化较硬体动物的化石化形成较少，符合it的指代，即it指代软体动物的化石化；B的后面也对促进软体动物的化石化的conditions进行了细节描述，符合对special environment的细节展开。

例3

One of the questions archaeologists strive to answer is why and how writing systems developed. The simplest answer is that they developed out of necessity. The most commonly accepted theory is that,as people began living in farming societies and, later,in more complex civilizations, bureaucracles expanded to organize and regulate people's affairs.■ They desired to keep accurate counts of certain things,so,as a result, various systems of counting and nothing what was being calculated were developed.■From this, scholars have surmised that the Sumerian writing system called cuneiform developed in Mesopotamia.■Interestingly,most of the extant clay tablets wit cuneiform on them deal with bureaucratic matters such as the amount of grain produced somewhere.■

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

Ino ther instances,however, literature,like the Epic of Gilgamesh was recorded in cuneiform.  

Where could the sentence best fit?

先阅读待插入句，however是一个逻辑暗示，可以得出待插入句跟它的前一句话应形成语义逻辑上的转折关系。in other instances本身也可以看成是一个逻辑暗示，说明待插入句应该是前文某一个核心概念或观点的例证，另外其中的other是一个指代暗示，可得前文应该以出现了一个相关例证。通过待插入句我们还能找出cuneiform这一核心概念，得到重复暗示，并得知这个举例就是关于cuneiform的举例（literature...was recorded in cuneiform)。通过这些预判，我们来看四个选项前后的关键信息。从重复暗示可得，cuneiform一直到C前面才开始提到，能排除A和B。（且我们也可通过原文中指代暗示得到反推：如插在A，A句后面They的指代无法完成，如插在B，B句后面this的指代也无法完成。）接着我们看C，C句前面次提到cuneiform，且为...called cuneiform，即对它下了个定义，不是个例子，无法完成other instances的指代，且C前句话也无法跟待插入句形成转折关系。应选D，D前正是对于解释说明cuneiform的一个例证，且是deal with bureaucratic matters方面的，待插入句正好是另一方面（literature）的例证，符合however的轻微转折，也符合in other instances的指代。

通过以上三个例子我们不难看出，每个待插入句都会有一种或多种暗示，我们要做的就是找出这些暗示。所以做这类题时，一定要思路清晰，理清待插入句的基本意思，根据暗示做好对前后句的预判。这类题型我们可以分题型的做集中训练，对各种思路都熟练掌握后，这类题型我们也可以迎刃而解了。