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(xiàng)選擇題

When navigating a vessel,you().

A.can always rely on a buoy to be on station
B.can always rely on a buoy to show proper light characteristics
C.should assume a wreck buoy is directly over the wreck
D.should never rely on a floating aid to maintain its exact position

微信掃碼免費(fèi)搜題