管理幅度较小、管理层次较多的组织结构形态是()

A．纵向结构

B．层级结构

C．锥形结构

D．扁平结构

国内生产数字监控产品的厂家有哪些？

Those regions inhabited mostly by national minorities in the Northwest of the country are retarded in terms of social progress and economic development ______ the coastal provinces.

A．in relevance to

B．in conformity with

C．in relation to

D．in accordance with

同轴电缆有哪些参数？

1250显像管真的能达到1250线吗？为什么？逐行扫描与100HZ扫描能否同时实现？

信噪比的单位是什么？