泵轴一般是用（）材料制成的。
A．低碳钢
B．中碳钢
C．高碳钢
D．电源
参考答案：B
Mum__________ me to school as she knew it was important for me to receive education，but we were so poor then．
A．had sent
B．sent
C．would have sent
D．would send
客车80km/h下的紧急制动距离：AW0～AW2载荷下为≤190m；AW3载荷下≤215m。
