鱼在游泳时，产生前进动力的部位是[ ]
A．胸鳍和腹鳍
B．尾鳍
C．躯干部和尾部
D．所有的鱼鳍
答案：C
Monetarists believe that:（）
A. shifts in aggregate demand arise from changes in expectations.
B. monetary policy has a significant impact on aggregate demand.
C. money wages tend to adjust quickly when aggregate supply and aggregate demand are in disequilibrium.
