12.進行下顎全口義齒顎舌骨肌後窩(retromylohyoid fossa)邊緣成形(border molding)時,牙醫師應引導病人做何種動作?①舌頭舔下嘴唇 ②舌頭舔上嘴唇 ③舌頭舔雙側臉頰 ④舌頭舔硬腭 (A)①② (B)③④ (C)①③ (D)②④