社会保障被称为（）
A.减压器
B.调节器
C.安全阀
D.减震器
参考答案：B, C, D
It’s time that I my hair cut. It’s the fifth time that I to the barber’s shop.
A．had; have gone
B．have; have gone
C．have; went
D．had; go
论《雷雨》的结构特点
