luminous emissivity

例句：

1. 1.The luminous emission of the star is a mystery that has puzzled astronomers for centuries.
   这颗恒星的发光发射一直是天文学家困惑了数百年的难题。
2. 2.The luminous emission of the star is a mystery that has puzzled astronomers for centuries.
   这颗恒星的发光发射一直是天文学家困惑了数百年的难题。
3. 3. The luminous emission of the star is a mystery that has puzzled astronomers for centuries.
   这颗恒星的发光发射一直是天文学家困惑了数百年的难题。