classify by的用法和樣例：
例句
- Any of a breed of dogs originally developed in Europe as hunting dogs, having thick, curly hair of varying color, and classified by shoulder height into standard, miniature, and toy varieties.
髦毛狗，貴賓狗最初在歐洲用作獵狗的一種狗，毛髮厚而捲曲，顏色各異，依據其肩高分成標準型、迷你型和玩具型 - The books in the library are classified by subject.
圖書館的書是按科目分類的。
