超声波通过介质时的传递速度就是声能的传递速度。
参考答案:对
He twisted his ankle in skiing, with the _____ that he was unable to take his exams.
A.consequence
B.conclusion
C.preference
D.prejudice
企业向受托方发出委托加工物资所需耗用的物资时,可能借记的会计科目有( )。
A.原材料
B.材料成本差异
C.委托加工物资
D.商品进销差价