第16题: [单项选择]Nerve signals may travel through nerve or muscle fibers at speeds as high as two hundred miles per hour. A. velocities B. impulses C. ratios D. atrocities 参考答案:A 答案解析:[解析] 本句意思是“神经信号在神经及肌肉纤维里以每小时200公里的速度传递”。speed“速度”;velocity“速度,快速”。例如:The car was moving at such a ve