单项选择题
Before the oily water is installed on board ships, it must have （）
A.IOPP B.type approval certificate C.cargo ship safety equipment certificate D.cargo ship safety certificate
单项选择题 The International Air Pollution Prevention Certificate (IAPP) is issued to（）
单项选择题 The International Sewage Pollution Prevention Certificate (ISPP) is issued to （）
单项选择题 The IOPP certificate is valid for （）
