在解决一些数学问题时,常常会遇到处理几个结论之间是“且”还是“或”的问题,有些同学因为没有把握“且”与“或”的意义与用法而出错.实际上,“且”表示几个结论“必须同时成立”的意思,“或”则表示几个结论“有其一成立即可”的意思.现举出几例加以说明,以供同学们参考. When solving some mathematics problems, it often comes up to deal with the problem of “and” or “or” between several conclusions. Some students have made mistakes because they do not grasp the meaning and usage of “and” and “or”. In fact, “And” means that several conclusions “must be established at the same time” mean, “or” means that several conclusions “has to be established.” Here are a few examples to illustrate for students to refer to.