符合铁路基建系统设备管理办法规定的类属划分的是（）
A.土石方机械
B.起重机械
C.砼机械
D.线路机械
参考答案：A, B, C, D
On Sundays there were a lot of children playing in the park, and _______ parents were seated together joking.
A．their
B．whose
C．which
D．that
管理评审就是质量管理体系的评审。
