食物蛋白质生物学价值是指
A.氮吸收量/氮摄入量
B.氮摄人量/氮吸收量
C.氮储留量/氮吸收量
D.氮吸收量/氮储留量
E.氮储留量/氮摄入量
参考答案:C
---Now, children begin to learn English at a very early age. It is really a good thing?
---_________.
A.Yes, just in case
B.Well, it depends
C.Don’t mention it
D.Believe it or not
长管(水力长管)