99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項選擇題

THE SPEED OF A VESSEL ADJUSTED TO THAT OF A PILOT BOAT AT WHICH THE PILOT CAN SAFELY EMBARK is ().

A.Ground speed
B.Boarding speed
C.Relative speed
D.Speed of the vessel

微信掃碼免費搜題