句子插入题

　　在每篇托福阅读文章的倒数第二题，固定地有这么一道题：原文一至两个段落中被挖出四个空，要求我们将一个额外的黑体句填到四个空中最合适的位置，也就是长下面例题这样：

　　On clear still nights when the heat island is pronounced, a small thermal low-pressure area forms over the city. ■Sometimes a light breeze—called a country breeze—blows from the countryside into the city. ■If there are major industrial areas along the outskirts, pollutants are carried into the heat of town, where they tend to concentrate. ■Such an event is especially probable if vertical mixing and dispersion of pollutants are inhibited. ■Pollutants from urban areas may even affect the weather downwind from them.

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

　　The resulting difference in atmosphere pressure between the city and the countryside can cause air to shift.

　　Where would the sentence best fit? Click on a square [■] to add the sentence to the passage. 

　　在以往的课堂上，当我问及学生为什么要把句子放在他们所选的位置的时候，无论选得对还是错，他们大多会高深莫测而又惴惴不安地回答我：感觉。对于总是做不对这个题型的同学，我惋惜他们一直被“错觉”操控；而对于这个题型正确率尚可的同学，我又担忧下一次他们马失前蹄，毕竟“感觉”实在是玄虚。

　　对于一道严肃的，旨在考察考生对句间逻辑关系和语法连接的理解的题型，仅用“感觉”二字来解释实在太过敷衍。所以，下面我就跟同学们探讨如何理性且自信地解决句子插入题。

　　句子插入题的基本解题步骤

　　1仔细阅读要插入的句子，有意识地找出线索,线索包括代词、定冠词词组、逻辑关系词、句意等。

　　2根据找出的线索对该句前、后的情形做出预测。

　　例如，插入句中有代词或定冠词the，说明该句的前面一定要有代词的先行词或具体指代的内容；插入句中有表并列关系的also、another等，说明该句前面有对另一同类事物的叙述；插入句有表转折关系的however、although等，说明该句和前文语意相反或相对；插入句中没有指代关系和其他逻辑关系可以利用，那么该句前面或后面应该会有信息的重复来确保句子与段落的语义联系。

　　3回到原文段落中找到符合预测的位置放入插入句。

　　4通读检查，确保逻辑和语义通顺、连贯。

　　接下来，我们根据以上所述的解题步骤来理性地分析几个例题。

　　例题1:

　　Along with the buildup of molecular oxygen (O2) came an eventual increase in ozone (O3) levels in the atmosphere. ■Because ozone filters out harmful ultraviolet radiation, this made it possible for life to flourish in shallow water and finally on land. ■This critical state in the evolution of the atmosphere was replaced between 1100 and 542 million years ago. ■Interestingly, the fossil record shows an explosion of life forms 542 million years ago.■

　　The timing strongly suggests that atmospheric changes were responsible for this sudden increase in new life.

　　认真阅读插入句，可知句意是“这个时间强有力地表明大气的改变是这次新生物突然增加的原因”。句中出现了定冠词词组“the timing”这个时间，以及明显的代词短语“this sudden increase in new life”这次新生物的突然增加。根据这两个线索，我们可以推测在插入句的前面一定提及确切的时间以及有关生物突然增加的内容。

　　回读原文段落，发现只有在第四个空之前的句子不仅提到具体的时间“542 million years ago”，且这句中的“explosion of life forms”生物大爆发即是插入句中“sudden increase in new life”的同义转述。最后通读检查，本段大意为在11亿年到5亿4千2百万年前，大气有一个臭氧增加的过程，臭氧能过滤有害紫外线的辐射，使得生物逐渐在浅海甚至陆地繁荣起来。而化石记录显示，刚好在5亿4千2百万年前有一次生物大爆发，这种时间的吻合强烈地表明这次物种爆发是因为大气改变。逻辑和语义通顺，答案稳妥。

　　例题2:

　　In some spiritual traditions, landscapes such as gardens or deserts were treated as abstract emblems of spiritual states such as innocence or despair. ■Rather than symbolic landscapes, as in the Judeo-Christian tradition, Greek sacred groves operated as literal homes of the gods. ■Instead of being confined to prehistory or celestial space, spiritual parkscapes were present within the existing cultural terrain. ■One could not visit a symbol of peace and severity, but one could experience these qualities in a sacred grove. ■

　　This, however, was not the Greek attitude.

　　本题插入句长度喜人，意为“然而，这并不是希腊人的态度”。句子虽短，但还是蕴含了丰富的线索。根据整体句意，我们不难看出这个句子是一个转折过渡句：句首代词this表明插入句之前应该有关于某种attitude的陈述，而句中最为显著的转折（however）意味使我们很自然地会想了解与前面attitude不同的Greek attitude具体是什么。

　　回到原文阅读发现，第一个空前后的情形符合我们的推测：这个空前面的句子讲了其他一些精神传统把花园抑或荒漠之类的景致看作是天真或是绝望等精神状态的象征，这可以看作是插入句中this的具体指代；然后插入句转折过渡一下“然而，希腊的态度并非如此”；紧接着后面一句说Greek attitude是什么，即希腊的神圣树林是作为神明的实实在在的家而非象征性的景观。

　　例题3

　　Raw materials, not equipment, constituted artisans’ major expense in most traders, however. ■Whereas in 1583 an Antwerp silk weaver paid 12 guilders for a loom (and made small payments over many years to pay off the debt for purchasing the loom), every six weeks he or she had to lay out 24 guilders for the 2 pounds of raw silk required to make a piece of cloth. ■Thus access to cheap and plentiful primary materials was a constant preoccupation for independent producers. ■Using local materials might allow even the poorest among them to avoid reliance on merchant suppliers. ■The loss of nearby sources could therefore be devastating. As silk cultivation waned around the Spanish cities of Cordoba and Toledo, weavers in these cities were forced to become employees of merchants who put out raw silk from Valencia and Murcia provinces. In the Dutch Republic, merchants who imported unprocessed salt from France, Portugal, and Spain gained control of the salt-refining industry once exploitation of local salt marshes was halted for fear that dikes (which held back the sea from the low-lying Dutch land) would be undermined.

　　This was possible because when transportation costs were low, the price of raw materials was generally also low.

　　首先理解插入句：这是可能的，因为当运输成本低的时候，原材料的价格通常也是低的。句中的线索比较容易就能抓到，代词this以及表因果关系的连词because。根据这两个线索，我们初步判定在插入句的前面会提到一个现象，这个现象跟插入句中because后面的内容要能成立合理的因果关系。而要达成因果关系合理这个目的，我们就需要根据已知的原因的内容对现象的内容进行大致地推测：现象必须蕴含交通运输成本低以及原材料便宜这层意思。

　　带着这些预判我们阅读原段，发现第四个空最合适：这个空前面的句子说“使用当地的原材料能让最贫困的工匠避免依赖供应商”，虽然没有直接说运输成本低、原材料便宜，但“local materials”本地原材料意味着运输不会有很多花费（试对比体会“老干妈”在中国和在美国的价格），“连最穷的工匠也买得起”也就暗示了本地原材料很便宜。

　　例题4:

　　Paragraph 1: It has long been accepted that the Americas were colonized by a migration of peoples from Asia, slowly traveling across a land bridge called Beringia (now the Bering Strait between northeastern Asia and Alaska) during the last Ice Age. █The first water craft theory about the migration was that around 11,000-12,000 years ago there was an ice-free corridor stretching from eastern Beringia to the areas of North America south of the great northern glaciers. It was the midcontinental corridor between two massive ice sheets-the Laurentide to the west-that enabled the southward migration. █But belief in this ice-free corridor began to crumble when paleoecologist Glen MacDonald demonstrated that some of the most important radiocarbon dates used to support the existence of an ice-free corridor were incorrect. █He persuasively argued that such an ice-free corridor did not exist until much later, when the continental ice began its final retreat. █

　　Moreover, other evidence suggests that even if an ice-free corridor did exist, it would have lacked the resources needed for human colonization.

　　插入句可译为：此外，其他证据表明，即使无冰走廊确实存在，它也会缺乏人类居住所必须的资源。句中包含了较多的线索：“moreover”表明插入句和前文是递进关系，对前文进一步论述；“other evidence”蕴含并列逻辑，可知前面应该已经提及某些evidence；宾语从句开头的让步“even if”，结合句意“即使ice-free corridor的确存在”，我们可以推测出，前文的evidence应该是在论证ice-free corridor不存在。根据这个推测，阅读原文发现第三个空前面一句话指出：Glen Macdonald证明了支持ice-free corridor存在的信息其实是错误的。这也就暗示了ice-free corridor不存在，符合我们对插入句前面情形的预判。

　　但出乎意料的是，第三空后面的内容依旧是在论述ice-free corridor不存在：他非常有力地指出，这种无冰走廊直到较晚的时期才出现。并且此句开头代词“he”，毫无疑问指代的是提出corridor不存在的Glen Macdonald，而插入句却并没有能够满足he这个指代的内容。所以，插入句应该放在第四空，让原文把关于corridor不存在的内容讲完，再递进和让步。

　　从例题4中我们可以进一步总结句子插入题的做题经验，放入插入句后通读检查是必要步骤，放入的位置不仅要能满足我们对插入句的上、下文的预期，还要确保插入句不影响原文某些本就紧密的句间关系，真正达到逻辑通顺、语义流畅。

　　以上内容希望能帮助同学们捋清句子简化题的解题思路，纠正一些对句间关系的“错觉”，之后能够在理性地指导下踏实地解题。