問題詳情

7 下圖為何種裝置？ 


(A)Lip bumper
(B)Wraparound retainer
(C)Tooth positioner
(D)Spring retainer

參考答案

答案：B[無官方正解]
難度：簡單0.8
統計：A(2),B(8),C(0),D(0),E(0)