5月GMAT机经考试难点之破折号的使用5月份GMAT考生SC中遇到破折号的情况频发，特此理清该知识点。
破折号号基本分为两种：长破折（Dash）和短破折（Hyphen）其中的长破折号的用法又分两种：single dash 和double dashHyphen 的用法很简单，是属于词语内部链接，比如the 15-year-old girl 啊，the man-eater 啊之类的，表示单词内部的修饰，说明，强调等等。
GMAT的SC中不太可能把这个设为考点。
但是Dash就不一样了，SC中经常遇到Dash的问题。
Single Dash：完全可以把其当做冒号（colon）,起到解释说明，强调，补充等等作用。
比如：Okay: Always buckle your seat belt; it's the law.Stronger: Always buckle your seat belt—it’s the law.Double Dash：可以把其当做括号（parenthesis），类似于插入语。
很插入语一样，在实际操作的时候，是完全可以把double Dash连同中间的内容一起删除的。
经典题目分析：OG13-132Although appearing less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year—they are often green and striped, or have plenty of bumps and bruises—heirlooms are more flavorful and thus in increasing demand.(A) Although appearing less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year(B) Although heirloom tomatoes, grown from seeds saved during the previous year, appear less appetizing than most of their round and red supermarket cousins(C) Although they appear less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year(D) Grown from seeds saved during the previous year, heirloom tomatoes appear less appetizing than most of their round and red supermarket cousins(E) Heirloom tomatoes, grown from seeds saved during the previous year, although they appear less appetizing than most of their round and red supermarket cousins如同插入语一样，在我们理解这句话的时候，可以把—they are often green and striped, or have plenty of bumps and bruises—删去，这样原句就变成：Although appearing less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year，heirlooms are moreflavorful and thus in increasing demand.(A) Although appearing less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year(B) Although heirloom tomatoes, grown from seeds saved during the previous year, appear less appetizing than most of their round and red supermarket cousins(C) Although they appear less appetizing than most of their round and red supermarket cousins, heirloom tomatoes, grown from seeds saved during the previous year(D) Grown from seeds saved during the previous year, heirloom tomatoes appear less appetizing than most of their round and red supermarket cousins(E) Heirloom tomatoes, grown from seeds saved during the previous year, although they appear less appetizing than most of their round and red supermarket cousins这样我们就发现这道题只能选B选项。
