单项选择题 A virtual rise in the center of gravity may be caused by（）.

单项选择题 A vessel is equipped with twin propellers，both turning outboard with the engines half ahead. If there is no wind or current and the rudders are amidships，what will happen?（）.

单项选择题 A twin-screw vessel with a single rudder is making headway. The engines are full speed ahead. There is no wind or current. Which statement is FALSE?（）.