But when you developmentally translate it to an absence of joyfulness, especially when joyfulness is the dominant mood state of young children, you have a pretty robust clinical marker.
但如果你把它理解成快乐缺失，尤其是小朋友们在以快乐为主导的年纪，你就答对了，这就是那个关键的东西。
2
As one of the important marker of human cell surface, HLA is the most complicated human dominant polymorphic genetic system because of its highly complicated polymorphism.