SAT语法的句子排序题，掌握了这些小技巧，可以帮同学们节省宝贵的做题时间

　　句子排序题通常要求同学们对不符合逻辑顺序的句子重新定位：

　　To make this paragraph most logical, sentence X should be

　　A) placed where it is now.

　　B) placed after/before sentence X.

　　C) placed after/before sentence X.

　　D) DELETED from the paragraph.

　　或者题目会给出一个句子，要求同学们判断这句话的正确位置：

　　The writer wants to add the following sentence to the paragraph.

　　The best placement for the sentence is immediately

　　A) after/before sentence X.

　　B) after/before sentence X.

　　C) after/before sentence X.

　　D) after/before sentence X.

　　破解句子排序题的关键并不是将四个选项一一代入原文(35分钟内完成44道题也不允许我们这样浪费时间，而是需要我们准确把握句子之间的逻辑关系，将需要定位的句子与原文进行逻辑上的匹配。那么，什么叫做句子之间的逻辑关系呢?一个段落内部的句子之间常见的连接方法主要有两种，即通过指代关系和逻辑关系词进行连接。

　　一、指代关系

　　除了常见的代词it/that之外，SAT语法考试中还常常通过重复上文关键词来连接两个句子，我们以OG Test 1 第1篇的第5题来说明如何根据句子之间的指代关系对句子进行快速定位：

　　[1] The main environmental problem caused by the production of Greek yogurt is the creation of acid whey as a by-product. [2] Because it requires up to four times more milk to make than conventional yogurt does, Greek yogurt produces larger amounts of acid whey, which is difficult to dispose of. [3] To address the problem of disposal, farmers have found a number of uses for acid whey. [4] They can add it to livestock feed as a protein supplement and convert it into gas to use as fuel in electricity production. [5] If it is improperly introduced into the environment, acid-whey runoff can pollute waterways, depleting the oxygen content of streams and rivers as it decomposes. [6] Yogurt manufacturers, food scientists, and government officials are also working together to develop additional solutions for reusing whey.

　　To make this paragraph most logical, sentence 5 should be placed

　　A) where it is now.

　　B) after sentence 1.

　　C) after sentence 2.

　　D) after sentence 3.

　　首先我们找到需要定位的第5句话：[5] If it is improperly introduced into the environment, acid-whey runoff can pollute waterways, depleting the oxygen content of streams and rivers as it decomposes.

　　我们先来提取一下这句话的主干，去掉第一个分句(条件状语从句)，去掉第三个分句(分词作状语)，这句话的主干只剩下acid-whey runoff can pollute waterways，清晰明了，句意为acid-whey runoff会污染河道。有的同学可能会问acid-whey runoff(含有酸性乳清的径流)是啥?然而个别专业术语不认识其实并不影响我们对文章的理解，紧迫的考试时间也不允许我们过多纠结生词，只需要在题本上划出句子主干，在脑海中反映出acid-whey这种物质会污染河道即可。

　　下一步我们需要从第1句开始对本段进行快速扫读，找到acid-whey第一次出现的地方。根据这个原则我们定位到了本段第2句话：[2] Because it requires up to four times more milk to make than conventional yogurt does, Greek yogurt produces larger amounts of acid whey, which is difficult to dispose of. 我们来提取一下这句话的主干，去掉第一个分句(原因状语从句)，去掉第三个分句(非限制性定语从句)这句话的主干只剩下Greek yogurt produces larger amounts of acid whey，即希腊酸奶会产生大量acid whey。

　　然而第2句的大意和第5句的大意并不足以支撑我们选出正确答案，因为只有在确认了第5句话和它前后的两句话之间有紧密的指代关系之后，我们才能准确定位。因此接下来我们继续扫读，在第3句中再次定位到acid-whey，第3句话的大意为：为解决处理acid-whey带来的问题，农民找到了它的很多用途。读到这里我们发现，第3句中提到的problem对应第5句中提到的acid-whey会污染河道。

　　将第2句，第5句和第3句连起来，我们得到这样的大意：希腊酸奶会产生大量acid whey;acid-whey会污染河道;为解决处理acid-whey带来的问题，农民找到了它的很多用途。因此本题正确答案是C。

　　有的同学比较谨慎，觉得还没有读完本段剩下的第4句和第6句，不敢直接作答。其实在考场上我们可以迅速扫读第4句话和第6句话来验证答案。

　　通过扫读第4句话：[4] They can add it to livestock feed as a protein supplement and convert it into gas to use as fuel in electricity production. 我们可以看出作者在具体解释acid whey有哪些农业用途，是对第3句末尾的详细展开。

　　然后第6句[6] Yogurt manufacturers, food scientists, and government officials are also working together to develop additional solutions for reusing whey. 的大意为多方合作重复利用whey，也是对acid-whey用途的探讨。至此，我们就可以放心的选出正确答案涂卡啦!

　　二、逻辑关系词

　　逻辑连接词同学们一定不陌生，because, but, therefore, for example这些词我们不仅常常见到，自己写作的时候还会经常用到。下面我们以OG Test 3 第3篇的第30题来说明如何根据逻辑关系词对句子进行快速定位：

　　[1] 1-MCP works by limiting a fruit’s production of ethylene, a chemical that causes fruit to ripen and eventually rot. [2] While 1-MCP keeps apples firm and crisp for months, it also limits their scent production. [3] This may not be much of a problem with certain kinds of apples that are not naturally very fragrant, such as Granny Smith, but for apples that are prized for their fruity fragrance, such as McIntosh, this can be a problem with consumers, who will reject apples lacking the expected aroma.

　　[4] But some fruits do no respond as well to 1-MCP as others do, and some even respond adversely. [5] Furthermore, some fruits, particularly those that naturally produce a large amount of ethylene, do not respond as well to 1-MCP treatment. [6] Take Bartlett pears, for instance: unless they are treated with exactly the right amount of 1-MCP at exactly the right time, they will remain hard and green until they rot, and consumers who experience this will be unlikely to purchase them again.

　　To make this paragraph most logical, sentence 4 should be placed

　　A) where it is now.

　　B) after sentence 1.

　　C) after sentence 2.

　　D) after sentence 5.

　　首先我们找到需要定位的第4句话：[4] But some fruits do no respond as well to 1-MCP as others do,and some even respond adversely. 我们先来理解一下这句话：但是有些水果对1-MCP的反应不像其他水果那么好，甚至有相反的反应。见到表示转折关系的but意味着这句话与上一句的句意相反，因此这句话的前文应该叙述了有些水果对1-MCP的反应很积极。

　　带着这样的预判，我们开始扫读本段的相关内容。在读到本段第2句时[2] While 1-MCP keeps apples firm and crisp for months, it also limits their scent production. 我们发现这句话的大意是：1-MCP可以让苹果果肉又紧又脆，且限制香味挥发。这句正是我们要找的描述“水果对1-MCP的积极反应”的句子。

　　为了验证答案，我们快速扫读本段第3句：[3] This may not be much of a problem with certain kinds of apples that are not naturally very fragrant, such as Granny Smith, but for apples that are prized for their fruity fragrance, such as McIntosh, this can be a problem with consumers, who will reject apples lacking the expected aroma. 这句话的大意是：对于本来没有什么香味的苹果，这不是个问题，然而对于香味浓郁的苹果来说，这个问题很严重。

　　由此我们得出第3句话中的a problem指的是香味都挥发掉了。结合第1句中“1-MCP可以限制有些苹果香味挥发”和第4句中“但是有些苹果的反应相反(即香味会挥发掉)”，我们可以判断出第3句的a problem指的正是第4句中香味会挥发掉这个问题，因此可以确定答案是B。