实验材料:紫色卷心菜、一把刀子、一块案板、开水、两个碗、一块干净的白布、一把木勺、夹子、绳子、牛奶、汤、柠檬汁、碳酸氢钠。实验步骤:请一位成年人帮你切开紫色卷心菜,放在一个碗里。小心地往碗里倒些开水,用木勺慢慢搅拌,紫色的卷心菜会把热水染成蓝色。把蓝色的水倒入另一个碗里。让蓝色的水冷却。现在,你已经有了能够区分酸、碱和中性物质的指示剂了。 Experimental materials: purple cabbage, a knife, a chopping board, boiled water, two bowls, a clean white cloth, a wooden spoon, clip, rope, milk, soup, lemon juice, sodium bicarbonate. Experimental steps: Ask an adult to help you cut the purple cabbage, placed in a bowl. Carefully pour some boiling water into the bowl, slowly stirring with a wooden spoon, purple cabbage will be hot water dyed blue. Pour the blue water into another bowl. Let the blue water cool. Now you have an indicator that separates acids, bases, and neutrals.