我国公务员录用的原则中，应该（）。
A.以公开为核心
B.以竞争为核心
C.以平等为核心
D.以择优为核心
参考答案：B
下列情况下，有相变的是（）
A、液态金属结晶
B、晶粒粗细的变化
C、磁性转变
Monopolistic competition differs from pure monopoly in that:（）
A. barriers to entry are high under monopoly, but low under monopolistic competition.
B. monopolistic competitors are price takers, monopolists are not.
C. monopolistic competitors face downward sloping demand curves, monopolists do not.
