在化学教学中，每当做到Ｃｌ２、ＳＯ２的制取和性质实验及用铜跟硝酸反应等实验时，就担心有毒气体危害师生身体健康。“瓶中瓶”实验装置集气体的制取装置和性质实验装置于一体，使用它做上述化学实验不仅现象明显、省时省药，而且可防止有毒气体的危害。具体操作和现象如下? In chemistry teaching, whenever the experiments on the preparation and properties of Cl2, SO2, and the reaction with copper and nitric acid are performed, there are fears that toxic gases are harmful to the health of teachers and students. The “bottle in bottle” experimental device integrates the gas preparation device and the nature experimental device into one. Using it as the above chemical experiment not only has obvious phenomena, saves time and medicine, but also can prevent the harm of toxic gases. The specific operations and phenomena are as follows?