九年级粤教版“空气中氧气含量的测定”实验,实际教学中存在以下问题:条件较差的偏远学校不能完成;还有部分教学经验不足的青年教师做不出应有的实验效果;少数教师怕受到五氧化二磷的毒害而不愿意做实验。因此,学生只能死记硬背实验,获得的知识仅仅停留在浅层的记忆表面,时间稍长就会忘记,不能牢固掌 Ninth grade Cantonese version of “air oxygen content determination ” experiment, the actual teaching of the following problems: poor conditions of remote schools can not be completed; there are some lack of teaching experience of young teachers can not do the proper experimental results Few teachers are afraid of being poisoned by phosphorus pentoxide. Therefore, students can only rote memorization experiment, access to knowledge only stay in the shallow memory surface, a little longer will forget, can not firmly palm