RBN造句怎麼寫

索引檔案中最低一級的索引塊,其內容包括相對塊號(RBN)和幾個資料塊的高一級的關鍵字。

Some 17 traffic-control systems have been established, 300 navigation aids set up or upgraded, and 20 RBN-DGPS stations in coastal ports and crucial waters established, basically achieving the target for completing the nation's navigation aid chains.