用于分割并列成分。考研重点：两个逗号之间，或者一个逗号之后，如果是补充说明成分时，跳过不看。Eg. Some huge American industries, such as consumer electronics, had shrunk or vanished in the face of foreign competition.
②用于某些缩略词之后。比如Mr.、 Ms.、 etc。等等。如果句号作为简写符号使用，那么这个词语简写前后面的符号应该照常写上，因为简写号并非句号，也不遵循句号的语法。比如Entreprise Co., Ltd或者I invited Tom, Jerry, etc..(注意两个点)。
Eg.1997 passage 3 Q2
60. The word "pervasive" (Line 1, Paragraph 2) might mean ________。
[A] widespread [B] overwhelming
[C] piercing [D] fashionable
We live in a society in which the medicinal and social use of substances (drugs) is pervasive: an aspirin to quiet a headache, some wine to be sociable, coffee to get going in the morning, a cigarette for the nerves。
For us, this means that evolution is over; the biological Utopia has arrived. (2000 Passage2)
①引用 ②强调 ③讽刺
Eg1 "Scientific" creationism, which is being pushed by some for "equal time" in the classrooms whenever the scientific accounts of evolution are given, is based on religion, not science。
Drugs (substances) that affect the central nervous system and alter perception, mood, and behavior are known as psychoactive substances. (1997，Text 3)
I am an idiot - the stupidest kind of all。
"This book stands for reason itself。" And so it does - and all would be well were reason the only judge in the creationism/evolution debate。
In Australia-where an aging population, life-extending technology and changing community attitudes have all played their part-other states are going to consider making a similar law to deal with euthanasia。
英文中的省略号的作用和汉语是一样的。当省略号在句围并且有下文时，应该打四个点，最后一个为句号。如：And it flew further, and further, and further.... Jorge smiled and turned back。当省略号在句尾并作为语气延长的作用时，应使用修辞前的标点，如：Do you love me...?其余情况下使用三个点。如：The Martians...they just...just bombed our...our town, please send...more.