It should be set to an arithmetic expression that has an integer as a result. 它設置了一個完整的數學表達應該能得到一個完整的結果。
For such a step to be firm, one would have to understand the basic concepts of mechanics and their mathematical expressions. 為使這一步堅實，必須理解力學的基本概念，以及它們的數學表達形式。
滬公網安備 31011502000490號
電信業務許可證編號：滬B2-20190700
