Also within each zone are portions of airspace, about 50 miles (80.5 km) in diameter, called TRACON (Terminal Radar Approach Control) airspace.是什么意思_Also within each zone are portions of airspace, about 50 miles (80.5 km) in diameter, called TRACON (Terminal Radar Approach Control) airspace.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句