一个低通信号m（t）的频带范围为0~108kHz，则可以无失真恢复信号的最小采样频率
A、0
B、216
C、54
D、108

A．未经韩某同意，韩某辩护人不得申请赵某回避
B．赵某所在法庭庭长可以指令赵某回避
C．作出回避决定之前，赵某不应停止本案的审理工作
D．赵某可以主动要求回避

A．An economy can produce at any point inside the production possibilities frontier, but not on or outside the frontier.
B．An economy can produce at any point on or inside the production possibilities frontier, but not outside the frontier.
C．An economy can produce only on the production possibilities frontier.
D．An economy can produce at any point inside or outside a production possibilities  frontier.