单项选择题
What is the main purpose of dunnage（）.
A.To act as ballast for light vessels B.To provide ventilation and drainage for cargo C.To secure the tarpaulins in place D.To support weakened bulkheads
单项选择题 What is the bow type anchor shackle primarily used for（）.
单项选择题 What is NOT running rigging（）.
单项选择题 What is normally used to pass a mooring line to a dock（）.
