SAT是Scholastic Aptitude Test的缩写，是申请几乎所有美国大学必须参加的考试。通常，希望继续接受高等教育的高中生需要参加SAT考试，并且SAT考试得分是获取奖学金的重要标准之一。大部分美国大学要求SAT考试作为录取的条件并根据SAT得分授予奖学金。

　　逻辑主语问题是SAT语法部分的一个常见问题，对于句子修改题(Improving Sentences)而言更是如此。为了帮助SAT考生迅速理解这个问题并掌握解决办法，本文拟从它的常见形式与修改方法两个方面进行阐述。

　　一 常见形式
　　逻辑主语问题的常见形式有下列几种：

　　1. 句子以现在分词开始
　　例如，
　　Lacking good instruction, my mistakes in creating a graph to illustrate historical trends were numerous. ( 句子以现在分词lacking开始)
　　(A) my mistakes in creating a graph to illustrate historical trends were numerous
　　(B) I made numerous mistakes in creating a graph to illustrate historical trends
　　(C) there were numerous mistakes in the graph I created to illustrate historical trends
　　(D) I created a graph to illustrate historical trends with numerous mistakes
　　(E) The graph I made for illustrating historical trends had numerous mistakes

　　2. 句子以过去分词开始
　　例如，
　　Carried by the strong, dry winds of the stratosphere, the 1980 eruption of Mount Saint Helens caused dust that crossed the United States in three days and circled the globe in two weeks. (句子以过去分词carried开始)
　　(A) the 1980 eruption of Mount Saint Helens caused dust that
　　(B) Mount Saint Helens’ eruption in 1980 caused dust that
　　(C) dust from the 1980 eruption of Mount Saint Helens
　　(D) dust from the 1980 eruption of Mount Saint Helens that
　　(E) there was dust from the 1980 eruption of Mount Saint Helens and it

　　3. 句子以介词加分词开始
　　例如，
　　By simply entering an internet website or calling a toll-free number, a catalog order can be placed for almost anything from cheesecakes to fully equipped desktop computers. (句子以介词by加分词entering…or calling…开始)
　　(A) a catalog order can be placed
　　(B) by placing a catalog order
　　(C) they will place your catalog order
　　(D) you can place a catalog order
　　(E) your catalog order can be placed

　　4. 句子以连词加分词或形容词开始
　　例如，
　　While driving down the road, the house with the large yard and small pond attracted the family’s attention.
(句子以连词while加分词driving down…开始)
　　(A) the house with the large yard and small pond attracted the family’s attention
　　(B) the house having the large yard and a small pond attracted the attention of the family
　　(C) the house with the yard and small pond was attractive to the family’s attention
　　(D) the family’s attention was attracted by the house with the large yard and small pond
　　(E) the family was attracted to the house with the large yard and small pond