刮黄油球时应掌握好黄油的（）。
A、水分
B、溶化温度
C、软硬度
D、环境条件
参考答案：C
— Mom, I' m going to the graduation dance tonight but I don' t think I look attractive enough.
— Oh, darling, don' t worry. ______. [ ]
A. They don't know what beauty is
B. Nobody will care about it
C. You look perfect the way you are
D. Impossible is nothing
拔除下颌牙时，病员的头位应为（）
A．头后仰使下颌面与地面呈90°角
B．头后仰使下颌面与地面呈60°角
C．头后仰使下颌面与地面呈45°角
D．头后仰使下颌面与地面呈30°角
E．头后仰使下颌面与地面平行
面与地面呈90°角