股骨颈内收型骨折是指Pauwels角（）。
A.大于50°
B.大于30°
C.小于30°
D.小于50°
E.等于30°
参考答案：A
Not until the press reported the pollution _________ why the water supply had been cut off.
A．people did know
B．people had known
C．did people know
D．had people known
护理质量管理的基本原则包括：（）
A.以患者为中心的原则
B.系统化方法原则
C.全员参与原则
D.过程方法原则
E.持续改进原则
