水封槽的有效高度应等于()加500mm。
参考答案:煤气计算压力
内部控制的及时性原则是指托管业务的各项经营管理活动都必须有相应的规范程序和监督制约。()
I've always__________Deng Xiaoping for his courage and determination to push China forward.
[ ]
A.looked down on
B.looked up to
C.looked around for
D.looked forward to