按照教材上的装置和方法实验 ,不足之处是 :往往试管里固化硬结的酚醛树脂很难取出 ,即使加乙醇浸泡 ,也只能溶解软化表面部分树脂 ,效果不佳 .如采用下列改进方法 ,则快速方便 ,十分有效 .每组学生发给一根一端弯成直角平钩的玻璃棒 (制作方法 :在喷灯火焰上把玻璃棒一端烧软 In accordance with the teaching materials and methods of experiment, the inadequacies are: often hardened phenolic resin in the test tube is difficult to remove, even if soaked in ethanol, it can only dissolve the softening of the surface part of the resin, the effect is not good. If you use the following improvements, It is quick and easy and very effective. Each student sends a glass rod with one end bent into a right-angled flat hook (method of making: Burning the glass rod end on the torch flame)