注意：此页面搜索的是所有试题
（2分）
ATo determine the position of a ship.
BTo find the direction of a current.
CTo predict the direction of a ship.
DTo carry message across the ocean.
ATo determine the position of a ship.
BTo find the direction of a current.
CTo predict the direction of a ship.
DTo carry message across the ocean.
参考答案