以下哪项属预防成本：（）。
A.进货检验费
B.劳务费
C.培训费
D.办公费
参考答案：C
人体气血化生之源的脏是
A．肾
B．心
C．肝
D．肺
E．脾
Which of the words in the sentence "There are too many facts here for me to digest them all. " is a metaphor ().
