底面直径和高都是4cm的圆柱的侧面积为______cm2.
∵圆柱的底面直径和高都是4cm,
∴圆柱的底面圆的周长是2π×2=4π
∴圆柱的侧面积是4π×4=16π,
故答案为:16π.
We wondered __________ this afternoon.
A.whether we would have a meeting
B.where would we have a meeting
C.whether we will have a meeting
D.that we would have a meeting
患者,女,13岁,面中1/3略突,面下1/3高度正常,上颌前牙舌倾,下前牙直立,磨牙轻远中关系,上颌拥挤4mm,下颌拥挤1mm
对此患者采用方丝弓矫治器治疗时应配合使用()
A.扩弓装置
B.上颌垫
C.Ⅲ类牵引
D.口外力牵引装置推磨牙向远中
E.功能性矫治器