水泥砼拌合时，拌合物的总量至少应比所需量高（）以上。
A.10%
B.15%
C.20%
D.25%
参考答案：C
Your father is sleeping. You'd better ___________.
A．not to wake him up
B．not to wake up him
C．not wake up him
D．not wake him up
挤压机减速器技术特性有哪些？
