（单词翻译:单击）
| O | |
| on occasion | 有时,不时 |
| occur to | 被想到,被想起 |
| at odor (with) | (与)…不一致;差异,争执 |
| off and on | 断断续续,不时的 |
| and so on | 等等 |
| all at once | 突然,同时,一起 |
| at once | 立刻,马上 |
| once (and) for all | 一劳永逸,限此一次 |
| once more | 再一次,又一次 |
| one another | 相互 |
| by oneself | 独自的,单独的 |
| come/go onto operation | 开始运转,开工 |
| put/bring into operation | 使投入生产,使运转 |
| in order | 秩序井然,整齐 |
| in order to | 以便,为了 |
| in order that | 以便 |
| out of order | 发生故障,失调 |
| put in order | 整理,检修 |
| every other | 每隔一个的 |
| other than | 不同于 |
| out of | 丧失,失去;缺乏,没有 |
| over and over (again) | 一再,再三 |
| owing to | 由于 |
| on one’s own | 独自的,独立的 |
