短语词组短語bell shaped insulator 鈴式絕緣子;鍾狀絕緣子triple petticoat bell shaped insulator 三裙豌式絕緣子bell shaped suspension insulator 碗形懸掛絕緣子double -bell insulator 雙碗形絕緣子bell -shaped suspension insulator 裙式懸垂絕緣子;鍾形懸掛絕緣子 返回 bell insulator