标点

GMAT的SC部分常会遇到四种标点：

逗号(，)是最常见的标点，也是最难使用正确的标点，不过GMAT考试很少以标点作为考点并通过逗号来判断正确选项。关于逗号记住：

不要用逗号连接两个句子。

当句子中两个谓语动词发起者是同一个人时，不要在and 前面加上逗号。

　　◆ Wrong: Earl walked to school, AND later ate his lunch.

　　◆ Right: Earl walked to school AND later ate his lunch.

　　◆ Right: Earl walked to school, AND HE later ate his lunch.

分号(;)连接两个相关的语句，每个部分都可以独自站立作为一个句子，但是如果句意上前后两者是有从属关系的则不能用分号：

　　◆ Right: The dam has created dead zones, WHERE fish have disappeared.

　　◆ Wrong: The dam has created dead zones; fish have disappeared.

分号又常常同些连接副词一起使用，如however, therefore, or in addition ，注意这些词和连词and 等又完全不相同，所以对于这些词，常常使用分号进行连接：

　　◆ Wrong: Andrew and Lisa are inseparable, THEREFORE, we never see themb apart.

　　◆ Right: Andrew and Lisa are inseparable; THEREFORE, we never see them apart.

而另一种比较少用的分号使用方法是将同一类的东西分开，而这些东西之间是用逗号分隔的：

　　◆ Wrong: I listen to Earth, Wind & Fire, Wow, Owls, and Blood, Sweat & Tears.

　　◆ Right: I listen to Earth, Wind & Fire; Wow, Owls; and Blood, Sweat & Tears.

冒号(:)为之前的事提供进一步的解释，说明。冒号前的通常是一个句子，可以独立存在，而冒号后则无需是句子，而有时会在冒号后加入namely 或that is。

　　I love listening to many kinds of music:

　　namely, classical, rock, rap, and pop.

要说明的部分离冒号越近越好：

　　◆ Worse: Three factors affect the rate of a reaction: concentration, surface area, and temperature.

　　◆ Better: The rate of a reaction is affected by three factors: concentration, surface area, and temperature.

破折号( - )是一个灵活的标点符号，GMAT考试中偶尔会用到。有时破折号可以代替逗号来使用：

　　By January 2, 2000, the so-called “Y2K problem” was already widely considered a joke—although the reason for the non-event was the huge corporate and governmental investment in prior countermeasures.

但有时候破折号又是必须的：

　　My three best friends—Danny, Jimmy, and Joey—and I went skiing.

这句话如果用逗号就会让人误以为有七个人go skiing 。破折号有时用来解释或重复之前句子的某个部分，但不像冒号需要紧跟着需要解释的词前面：

　　Post-MBA compensation for investment bankers tends to surge far ahead of that for management consultants—by tens, if not hundreds, of thousands of dollars a year.

上面的这个例子中by tens, if not hundreds, of thousands of dollars a year 解释句子前面的far。