单项选择题
Electrical wiring on all T-Boats must be（）.
A.concealed to prevent mechanical damage B.concealed so the boat can be maintained more easily C.protected from the weather D.in an accessible place behind the ceiling
单项选择题 DO NOT，REPEAT，NOT OVER-TAKE means that you should（）.
单项选择题 By regulation，you MUST keep a record of the use of your radiotelephone for at least（）.
单项选择题 Automatic identification systems (AIS) are required to（）.
