一次旅行用英语可以说成 "a trip". 这个词来自英语中的 "trip"，意思是 "旅行，游历，旅程"。

例句：

I'm going on a trip to Paris next month. (我下个月要去巴黎旅行。)

My parents took me on a trip to Disney World when I was a child. (我小时候父母带我去迪斯尼世界旅行。)

My friends and I are planning a trip to Thailand for our summer vacation. (我和朋友们正在计划去泰国度假。)