You could make a choice from obtaining just one system as a just one-off buy, or you can sign up for an once-a-year subscription which gives you entry to all BBC Maestro classes for one particular calendar year.知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。a summary 「まとめ」は「a summa