one at a time

adv. 每次一个

例句与用法：

They don't get on at all well together/with one another.

他们彼此极不和。

The two rooms open into one another.

这两个房间有门相通。

The students vary from one another in character.

学生们的性格各不相同。

They three get along well with one another; one is married, another is still a bachelor, and the other has a girl friend.

他们三人彼此相处愉快; 一个已婚，一个仍是光棍，而另一个则已有了女友。

Sadness and gladness succeed one another.

[谚]乐极生悲，苦尽甘来。

The Irish is a fair people; they never speak well of one another.

爱尔兰人是公平的人民，他们决不互相称赞。

You should help one another.

你们应该互相帮助。