最近,笔者有幸带学生参加了一个市级的实验操作比赛,比赛组委会给选手们呈现了如下一组材料:材料1:在约旦和巴勒斯坦之间有个咸水湖,湖里的水含盐量比普通的海水高出6~7倍,不会游泳的人掉进水里也不会淹死,有许多游客还浮在水面上读书、看报。操作要求:请选择合适的方法和器材让红薯浮出水面(桌上给出了烧杯、红薯、玻璃棒、盐、小刀等 Recently, I was fortunate to bring students to participate in a municipal experimental operation contest, the organizing committee presented to the players a set of materials as follows: Material 1: there is a salt lake between Jordan and Palestine, the lake water salinity 6 to 7 times higher than ordinary sea water, people who do not swim into the water will not drown, many tourists still floating on the water reading, reading newspapers. Operating requirements: Please select the appropriate method and equipment for the sweet potato surfaced (the table gives a beaker, sweet potato, glass rod, salt, knife, etc.