单项选择题 According to Annex I of MARPOL 73/78, oily waste from cargo tanks of oil tankers can be discharged when the ship is more than（）away from the nearest land.

单项选择题 The MARPOL Convention is the main international convention（）

单项选择题 At an unsheltered anchorage the chief engineer officer shall consult with the master whetheror not to maintain an underway watch“An underway watch” means（）