托福閱讀長難句分析:鍵盤樂器

　　In the seventeenth century the organ, the clavichord, and the harpsichord became the chief instruments of the keyboard group，a supremacy they maintained until the piano supplanted them at the end of the eighteenth century.

　　(同位語a supremacy)

　　17世紀時風琴、敲弦琴和撥弦琴成為鍵盤樂器類的主要成員，這種至高無上的地位一直由它們保持，直到18世紀末被鋼琴所取代。

　　分句1：In the seventeenth century the organ, the clavichord, and the harpsichord became the chief instruments of the keyboard group，

　　分句2：a supremacy

　　分句3：they maintained until the piano supplanted them at the end of the eighteenth century

　　分句2是分句1的同位語，用來修飾說明分句1中的the chief instruments of the keyboard group，分句3是省略了 "that" 的定語從句，修飾分句2.