Warning: file_put_contents(/www/wwwroot/ppbbu/laei.cn/cache/35b61d6f9dff899c804a22ade268dc69.txt): failed to open stream: No space left on device in /www/wwwroot/ppbbu/laei.cn/index.php on line 58 planetary nebula英英字典_planetary nebula剑桥英语解释_planetary nebula柯林斯英文解释_按摩法牛津词典
1. N an expanding shell of gas surrounding a dying star, formed from matter ejected from the star's outer layers; the gas is ionized by the remaining hot stellar core, emitting light in the process 行星狀星雲