保持商品的数量和质量不变的包装属于()。
A．单个包装
B．组合包装
C．工业包装
D．商业包装
参考答案：C
______ is clear is that some voluntary code of practice among scientists has to be agreed.[ ]
A. As
B. That
C. What
D. It
实行电算化后，总账对其下属明细账的统御关系仍然存在。( )
