4) 破折号(Dash)
主要用于：
a) 注释性的词语或句子前；如用于句子中间，前后都要有破折号。例如：
There is a way to decide any question — experiment.
Somewhere or other — I think it is in the preface to Saint Joan — Bernard Shaw remarks that we are more gullible and superstitious today than we were in the Middle Ages.
b) 补充性的成分。例如：
Life — and death, too — is a cycle that goes round and round. I teach because teaching is a profession built on change. When the material is the same, I change — and more important, my students change.
c) 总括所列举的事物。例如：
The complex operation required new methods for directing the combined endeavors of thousands and thousands of minds, some in government, some in universities, some in private industry — all working together for a common purpose.
d) 突然转折。例如：
One little problem is that a computer can’t laugh yet — but the scientists are working on it.
5) 撇号
a) 用作省略号。例如：o’er ( = over), it’s = (it is).
b) 用作所有格符号。例如：Mary’s handbag, the l990’s。
c) 构成字母、数字或缩写的复数形式。例如：the four a’s。
EXERCISE l
Capitalize and punctuate the following:
1．the man’s papers Betty found in the attic established his identity It henry bedell company D 11th vermont volunteers 30 years old
2．it was clear that dad could do no more than he was doing already farming 80 acres in addition to holding a fulltime job
3．now i’m coming to the most important point but what are you doing over there
4．rain snow sleet fog would not trouble the underground world
5．during the summer the resort is crowded with tourists during the winter only sea gulls walk the beach
6．to a certain extent mankind encumbers the earth
7．1ike most wild life deer reproduce grow and store fat in the summer and fall