已知一条弧的长是2π厘米,弧的半径是8厘米,则这条弧所对的圆心角是______度.
设所对的圆心角是n度,根据题意得:8nπ180=2π,
解得:n=45,
故答案是:45.
设置两套系统的组织结构是()
A.直线型
B.职能型
C.直线-参谋型
D.分部型
E.委员会
John opened the door. There _______ he had never seen before. [ ]
A. a girl did stand
B. stood a girl
C. a girl did stood
D. did a girl stand