“必须“”、必需”:“必须”表示一定要那样做,不那样不行,如“必须实行法治”;“必需”表示一定得有,不可缺少,如“油盐酱醋是生活必需品”。“变换“”、变幻”“:变换”意为事物的一种形式或内容换成另一种,其过程或结果一般是具体的,以至是可以看得见的,如“变换位置、变 “Must” and “necessity”: “Must” means that we must do that, but not so, such as “the rule of law must be implemented”; “required” means that there must be, indispensable, such as “oil and salt vinegar is a necessity of life.” “Transformation”, “changing” and “transformation” mean that a form or content of something is changed to another, and the process or result thereof is generally specific, so that it can be seen, such as "change position, change