氧气是初中《化学》中介绍的三种重要气体之一 .对氧气知识的考查也是历年各地中考命题的热点 ,且题型不断变化 .现将近几年出现的题型归纳如下 :一、方案评价型例 1　为保证长时间潜航 ,在潜水艇里要配备氧气再生装置 .有以下几种制取氧气的方法 :①加热高锰酸钾 .②电解水 . Oxygen is one of the three important gases introduced in “Chemistry” of junior high school. The examination of oxygen knowledge is also a hot topic of the propositions of the national examinations over the years. The types of questions are constantly changing. The types of questions that have emerged in recent years are summarized as follows: First, the program evaluation Model 1 In order to ensure long-term submergence, a submarine should be equipped with an oxygen regeneration device. There are several methods for preparing oxygen: 1 heating potassium permanganate. 2 electrolysis of water.