最新版初中物理第一册《质量和密度》的学生分组实验“用天平和量筒测定物质的密度”仍然沿用了旧教材中的实验步骤：即先测出石块的密度，再测定盐水的密度。看似无关紧要，但笔者在多年的指导学生实验的实践中，发现每次学生在实验完毕后测出的数据中石块的密度基本符合密度 In the latest edition of junior high school physics booklet “Quality and Density”, the student group experiment “Determination of Density with Balances and Graduated Tubes” still followed the experimental procedure in the old textbook: the density of stones was measured first, and the density of brine was measured. . It seems to be irrelevant, but in the practice of guiding students’ experiments for many years, the author found that the density of stones in the data measured by the students after the experiment is completed basically meets the density.