A metal tube in which a flow of gas is mixed with a controlled flow of air to concentrate the heat of a flame,used especially in the identification of minerals.是什么意思_A metal tube in which a flow of gas is mixed with a controlled flow of air to concentrate the heat of a flame,used especially in the identification of minerals.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句