If neither of these explanations is true, though, it may mean that a secondary and more lethal mutation has emerged recently, and is now spreading in its turn.是什么意思_If neither of these explanations is true, though, it may mean that a secondary and more lethal mutation has emerged recently, and is now spreading in its turn.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句