火焰原子吸收光度法可测定（），（），（）中的铁和锰。
参考答案：地面水；地下水；工业废水
给你一把钢锯条，你能做哪些声学实验？简要说明过程（举二例）
"You _____ smoke in the bedroom," Rose said to her husband and pushed him out of the room. [ ]
A. needn't
B. mustn't
C. dare not
D. won't
