单项选择题
A.They should wear safety shoes
B.They should wear ear protection
C.They should not wear jewelry
D.All of the above
单项选择题 The word "discharge" as used in Pollution Prevention Regulations applies to oil （）.
单项选择题 If fuel tank levels are found to have increased after a grounding, you should suspect （）.
单项选择题 An International Oil Pollution Prevention Certificate (IOPP) for a "new" vessel ceases to be valid if （）.