Either of the plans is satisfactory.
两个计划都令人满意。
There are trees on either bank of the river.
河两岸都有树。
It won't do them any good, but it won't do them any harm either.
这对他们没好处，但也没什么害处。
You can take either the blue pencil or the black one.
你可以拿这支蓝铅笔或那支黑铅笔。
You can either stay here or go with them.
你可以待在这儿，也可以和他们一起去。
Either you must improve your work or I shall dismiss you.
要么你好好改进工作，要么我就解雇你。
Either you or I am wrong.
不是你错就是我错。