On is Ok in your case?

来源: 于 2011-09-14 19:27:52 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

 

1on Listen to audio/ˈɑ:n/ preposition

15 — used to indicate an activity that someone did or is now doing ▪ She did well on the exam/test. ▪ The band is currently on tour. ▪ He is off/away on a trip/vacation. ▪ She is on a diet. ▪ The officers are on duty.

 
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