1. I have to dash.
2. He looks dashing.
3. Please use a dash between two nouns to when you want to make it an adjective.
1. I need to go right now. I need to go in a hurry. 我現在急著離開。
2. He looks handsome. 他看起來很英俊(英式英文)。
3. 指的是"-"，例: ex-girlfriend, one-day event, twenty-fourth day等。