下列哪项不属于在物联网存在的问题：（）
A、国家安全问题
B、隐私问题
C、标准体系和商业模式
D、制造技术
参考答案：D
A project manager has just been assigned to a new project and has been given the project charter．The FIRST thing the project manager must do is （）．
A．create a project scope statement
B．confirm that all the stakeholders have had input into the scope
C．analyze project risk
D．begin work on a project management plan
490KHZ为（）频率
A.国际NAVTEX
B.NAVAREA
C.国内NAVTEX
D.常规通信
