单项选择题
A.main switchboard
B.engine room bilge
C.breathing compartment
D.electric fresh water transfer pump
单项选择题 The International Oil Pollution Prevention Certificate is valid for a period of （）.
单项选择题 The International Oil Pollution Prevention Certificate required by MARPOL is issued to China flag by the （）.
单项选择题 Under the regulations implementing MARPOL, a mobile offshore drilling unit is required to have an International Oil Pollution Prevention (IOPP) certificate when the unit （）.