这两个都是可以的。

dash 破折号，用于两种情况一，重点突出破折号中的或后的内容The students—they were each over the age of eighteen—lined up in the streets to vote for the presidential candidates.二，举例子The salads available--house, Caesar, and Cobb--are all delicious.colon，冒号，用于三种情况。一，列出一列东西。二，用于两个独立分句中间，第二个句子解释第一个句子。Gems can be quite valuable: some cost millions of dollars.三，引出一句话