破折号（dashes）
1、用于突出强调句子中间的内容。
Our ideas for the weekend—going to a movie, having apicnic, doing homework, and hiking Garcia Trail—seemed like a lot to squeezein.
2、用于分隔句子后面的内容。
I knew the material perfectly—until test day.
We went to Slauson Park—the one north of Fifth Street.