当不能与在管制区内飞行的航空器保持()通信联络时,管制单位应当按规定程序采取措施。
A.5分钟
B.8分钟
C.10分钟
D.双向无线电
参考答案:D
A.,正电荷
B.,正电荷
C.,负电荷
D.,负电荷
Out of the following definitions of a project stakeholder, which one do you think is most appropriate ?()
A.An enterprise whose employees are directly involved in doing the project work
B.An entity whose interest may be affected as a result of the project execution
C.An entity that performs activities to accomplish objectives
D.One who is responsible for managing the project