旋涡 xuánwō HSK7 vortex Origin Definitions Defs Strokes Stroke Words Sentences Sents 旋涡星云 xuánwōxīngyún spiral nebula 准稳旋涡结构 zhǔnwěnxuánwōjiégòu quasi-stationary spiral quasi-stationary spiral structure (QSSS) in astrophysics旋涡星系 xuánwōxīngxì spiral galaxy 旋涡状 xuánwōzhuàng spiral spiral-shaped