单项选择题
Any vessel in need of carrying out deck washing must be（）by the department concerned beforehand.
A.requested B.allowed C.approved D.inquired
单项选择题 An obstruction on a helideck is any object that might present a hazard to the（）.
单项选择题 AN ILLNESS PREFERABLY OF AN INFECTIOUS NATURE SEIZING MORE THAN TWO PERSONS ON BOARD AT THE SAME TIME defines（）.
单项选择题 Aboard a survival craft，ether can be used to（）.
