18.取大豆樣品a克放入恆重為b克之稱量瓶內,再放入烘箱中乾燥,乾燥後含樣品之稱量瓶恆重為c克,樣品之固型物含量(%)計算式為:(A)[(c–b)/a]×100%(B)[(a+b–c)/a]×100%(C)[(b–c)/a]×100%(D)[(b–a)/a]×100%