IP协议提供了一种统一的（），屏蔽了物理地址的差异，使路由查找成为可能。
参考答案：编码方式
The effect of a price ceiling set above the equilibrium price is most accurately described by which of the following statements（）
A. It will have no effect on equilibrium price and quantity.
B. It will affect equilibrium price, but not equilibrium quantity.
C. Quantity demanded will exceed quantity supplied.
单晶样品在电子衍射时，在感光板上形成的衍射花样是（）
A.点花样、菊花线
B.环花样、菊花线
C.菊花线、线花样
D.线花样、点花样
