单项选择题
The Coordinator Surface Search in a SAR situation should display by day（）.
A.the code flags FR B.a black ball over a black diamond shape C.code flag Quebec over a black ball D.two black diamond shapes in a vertical line
单项选择题 Some sea water came into the wheel house during the voyage due to（）the window thereof.
单项选择题 If your vessel is dragging her anchor in a strong wind，you should（）.
单项选择题 Production of mechanical foam by a portable in-line foam proportioner（）.
