/wʌn ||; wʌn/pronoun det noun [C]
1 1 一: There's only one biscuit left. 只剩下一块饼干了。The journey takes one hour. 这趟旅程要花一小时。If you take one from ten it leaves nine. 十减一等于九。 ☞Look at first. 参看first。 ☞For examples of how to use numbers in sentences, look at six. 有关数词在句子里的示例，参看six。
2 (used when you are talking about a time in the past or future without actually saying when) a certain （表示非明确的过去或将来某段时间）某一: He came to see me one evening last week. 上星期的一个晚上他来看我。We must go and visit them one day. 我们得找一天去探访他们。
3 used with the other, another or other(s) to make a contrast （与the other、another或others连用以作对比）: The twins are so alike that it's hard to tell one from the other. 那对双胞胎如此相似，使人难以辨别出谁是谁。
4 the one used for emphasizing that there is only one of sth （用于加强语气）唯一: She's the one person I trust. 她是我唯一信赖的人。We can't all get in the one car. 我们这么多人一辆车坐不下。
(all) in one all together or combined 一起；合在一起:
It's a phone and fax machine all in one. 那是电话机和传真机二合一。 one after another/the other first one, then the next, etc 一个接一个；先后:
One after another the winners went up to get their prizes. 优胜者一个接一个上去领奖。 one at a time separately; individually 一次一个；单独地:
I'll deal with the problems one at a time. 我会逐一处理这些问题。 one by one separately; individually 个别地；分别地:
One by one, people began to arrive at the meeting. 人们开始逐一抵达会场。 one or two a few 少量；一些；一两个:
I've borrowed one or two new books from the library. 我从图书馆借了一两本新书。 *one²/wʌn ||; wʌn/pronoun noun[C]
1 used instead of repeating a noun （用于代替重复的名词）: I think I'll have an apple. Would you like one? 我想要个苹果，你要不要？
2 one of a member (of a certain group) 一组或一群…中的一个: He's staying with one of his friends. 他目前住在一个朋友家里。One of the children is crying. 孩子当中有一个在哭。
One of is always followed by a plural noun. The verb is singular because the subject is one One of our assistants is ill. One of the buses was late. one of后总是接复数名词。因为主语为one，应用单数动词：One of our assistants is ill.我们有一名助理人员病了。·One of the buses was late.有一辆公共汽车晚点了。 3 used after this, that, which or after an adjective instead of a noun （用于this、that、which或形容词后而不是名词后）: ‘Which dress do you like?’ ‘This one.’ “你喜欢哪件连衣裙？”“这一件。”‘Can I borrow some books of yours?’ ‘Yes. Which ones?’ “我可以向你借几本书吗？”“可以，哪几本？”‘This coat's a bit small. You need a bigger one.’ “这件外套小了一点，你需要一件大些的。”That idea is a very good one. 那主意很不错。
4 the one/the ones used before a group of words that show which person or thing you are talking about （用于一组词语前，指示所说的是哪个人或物）: My house is the one after the post office. 我的房子是邮局隔壁那一幢。If you find some questions difficult, leave out the ones you don't understand. 如果你觉得有些问题难答，就把不明白的略去。
5 (formal 正式) used for referring to people in general, including the speaker or writer （泛指人，包括表达意见者在内）: One must be sure of one's facts before criticizing other people. 在批评别人之前，一定要弄清事实。 ☞It is very formal to use one in this way. In everyday English it is usual to use you. one的这种用法很正式，日常英语通常用you。