单项选择题
A.30~60g B.60~150g C.100~150g D.60~350g E.350~500g
A.邻间钩 B.卡环 C.头帽 D.双曲舌簧 E.以上都不对
A.丝圈应离开牙槽嵴0.5mm B.丝圈应离开牙槽嵴0.5~1mm C.丝圈应离开牙槽嵴1~2mm D.丝圈应离开牙槽嵴2~3mm E.与牙槽嵴贴近