单项选择题
In anchor orders, “Up and down” means “（）”.
A. The chain is not upright B. The chain is upright C. The chain is slack D. The chain is not slack
单项选择题 The expression “Drop anchor” means “（）”.
单项选择题 According to the report, the ship hit the wharf when （）.
单项选择题 Keep clear of the （）!
