单项选择题
One of the main advantages of a graphite-furnace atomizer is that（）
A.It requires only very small quantities of a sample B.It requires metal.ions in aqueous solution C.It does not produce background emission like a flame D.It does not get hot like a flame
单项选择题 The purpose of the ashing step in graphite-furnace atomic-absorption spec-troscopy is to（）
单项选择题 The purpose of the flame in flame atomic-absorption spectroscopy is to（）
单项选择题 A hollow-cathode lamp is（）
