A report of casualty to a mobile offshore drilling unit must be made in writing to which office? ()
A. Commandant of the Coast Guard
B. Owner of the unit
C. Nearest Coast Guard Marine Safety Office
D. Captain of the nearest port
查看答案
超声波探伤仪是从电子管、晶体管到集成电路逐步发展起来的,虽然电路也变得越来越复杂,其核心结构已经不再是发射和接收超声波。
A. 正确
B. 错误