不合格玩具产品经整改后可重新报检，检验合格后放行。( )
参考答案：对
Which of the following inventory accounting methods must be used for financial reporting purposes if a U. S. firm uses last in, first out (LIFO) for tax purposes
A．
B．
C．
试述离心泵不上量不上压的原因及处理方法？
