规则八：
使用破折号来表示突然停顿或中断，引导一个较长的同位语或总结

破折号的分隔能力比逗号强，正式程度不如冒号，严谨程度不如圆括号。

例如：

His first thought on getting out of bed—if he had any thought at all—was to get back in again.

一想到起床，他的第一个想法——如果有任何想法的话——就是重新回到床上。

The rear axle began to make a noise—a grinding，chattering，teeth-gritting rasp.

后轮轴开始发出噪音——一种嘎吱嘎吱、咔哒咔哒磨牙般的刺耳声音。

The increasing reluctance of the sun to rise，the extra nip in the breeze，the patter of shed leaves dropping—all the evidences of fall drifting into winter were clearer each day.

太阳越来越懒得升起，风变得格外寒冷刺骨，落叶哗哗地坠落——所有的迹象都一天天逐渐清楚地表明秋去冬来。

只有当常见的标点符号不适用时才使用破折号。

例如：

Her father’s suspicions proved well-founded—it was not Edward she cared for—it was San Francisco.

她父亲的猜疑被证明是有理由的。她在意的不是爱德华，而是旧金山。

Her father’s suspicions proved well-founded. It was not Edward she cared for，it was San Francisco.

她父亲的猜疑被证明是有理由的。她在意的不是爱德华，而是旧金山。

Violence—the kind you see on television—is not honestly violent—there lies its harm.

暴力——你在电视上看到的那种——还不算是真正的暴力，但已经有危害了。

Violence，the kind you see on television，is not honestly violent. There lies its harm.

暴力，你在电视上看到的那种，还不算是真正的暴力，但已经有危害了。 vpQEdMLyJS3p49AApszOJwJw0bcFLMwtPCWo3gOQKn/N8h27TAuOU8YanVAfzPmr