英语翻译They involve abstracting the essential features of the p

英语翻译
They involve abstracting the essential features of the problem under study ,neglecting any factors judged to be unimportant,and postulating relationships precise enough to help answer the questions posed by the problem.However,these relationships must be simple enough to permit the completion of the remaining steps .Although these steps admittedly involve a degree of craftsmanship ,we will learn some scientific techniques we can apply to appraise the importance of a particular variable and the preciseness of an assumed relationship.Nevertheless ,when generating numbers in steps 3 and 4 ,remember that the process has been largely inexact and intuitive.