(同位語a supremacy)
17世紀時風(fēng)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.