【多选题】三相异步电动机产生过载的原因主要有( )。
【判断题】Walt Whitman is called the "Bard of Democracy" and considered one of America's most influential poets.
【判断题】Democracy is one of the consequences of economic growth and progress.
【多选题】三相异步电动机产生过载的原因主要有( )。
【判断题】One of Dickens’ writing features is the spirit of democracy and humanism.
【简答题】旋转机器产生不平衡振动的主要原因有哪些?
【简答题】动机产生的主要原因有____和____。