Unless some extra money is found, the theatre will close.
要是不能找到更多资金，剧院将要关闭。
I think you should complain – unless, of course, you are happy with the way things are.
我觉得你应该发发牢骚——当然，除非你对现状很满意。
He won’t go to sleep unless you tell him a story.
要是你不给他讲故事他就不睡觉。
I can’t leave her unless I know she’s all right.
除非我知道她没事，否则我不能离开她。
prep. 除…之外
besides、
except as、
in addition to