与填料密封相比，机械密封具有（）的特点。
A.密封性可靠
B.寿命长
C.摩擦消耗小
D.对旋转轴的震动不敏感
参考答案：A, B, C, D
__________ a terrible storm would attack the old town.
A．Word came that
B．Word that came
C．Word came which
D．Word comes that
床上洗头操作目的？
