It is reported in the newspaper that a man escaped from the prison last night and it was a long time

______ the guards discovered what had happened. [ ]

A. when          

B. until            

C. since        

D. before

关于骨盆出口平面，哪项不对

A．出口横径与后矢状径之和>15cm时，中等大小的胎儿可经 * * 分娩

B．骶尾关节至耻骨联合下缘之间的距离约为11.5cm

C．出口横径是坐骨结节间的距离，平均约为9cm

D．呈菱形

E．前矢状径约为6cm