单项选择题
Oil product samples should be taken from the（）.
A.dock riser B.ship's cargo tanks C.shore tank discharge D.All of the above
单项选择题 For any given pedestal crane，when the boom is lengthened，the lifting capacity is（）.
单项选择题 For a given weight of cargo，the stress on the heel block of a cargo boom（）.
单项选择题 Bonding cables are used during cargo transfer to（）.
