Herds of dugongs or sea cows -- some of which can reach three metres long -- ply the coastal waters, grazing on sea-grass.是什么意思_Herds of dugongs or sea cows -- some of which can reach three metres long -- ply the coastal waters, grazing on sea-grass.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句