直线定向采用盘左、盘右两次投点取中是为了消除()。
A.度盘偏心差
B.度盘分划误差
C.视准轴不垂直于横轴误差
参考答案:C
颞下颌关节的功能区是()
A.关节结节前斜面和髁突前斜面
B.关节结节后斜面和髁突后斜面
C.关节结节后斜面和髁突前斜面
D.关节结节前斜面和髁突后斜面
E.关节窝底和髁突顶
His parents will come back _______ an hour.
[ ]
A. after
B. in
C. later
D. behind