简述数字相位仪的测量误差产生的几个方面。
参考答案:
数字相位仪测量误差由以下几方面产生:①标准频率误差;②闸门触发误差;③脉冲计数误差;④不平衡误差;⑤外部电路引起的误差。
期货从业人员包括为期货公司提供中间介绍业务的机构中,从事期货经营业务的管理人员和专业人员。()
During the summer vacation, several provinces have ________distance learning to help their teachers to
improve their teaching skills and update their professional knowledge.[ ]
A. attended
B. adopted
C. adapted
D. admitted