先进先出法是:假设先入库的存货先发出,即按照存货入库的先后顺序,用先入库存存货的单位成本确定发出存货成本的一种方法。()The first-in-first-out method is a method to determine the cost of the issued inventory based on the unit cost of the first in stock, assuming that the first in stock inventory is issued first. ( )