有一无二

Explanation: Only one, not the second. That things unique, very rare. 　　Usage: Joint type; as predicate, attributive; describe a very rare 　　Source: Ming Yao sub-wing, "persuading the legendary land of Lord Jin," like this and so it is exactly the same tune is also considered as one of the. " 　　Examples: Saw such Liu Erdi probably know that my appearance is within the tai ~ of the ancient and modern. (Cao Xueqin, "Dream of Red Mansions," the 66th back) Thesaurus:  in a class by itself, Only this one, no other branch, This alone door