干瘦型营养不良所致主要原因有().
A.天然食物某些营养素缺乏
B.食物烹调过程中营养被破坏
C.人体胃肠道功能的降低
D.能量严重摄入不足所致。
参考答案:D
____ succeed in doing anything .
A.Only by working hard we can
B.By only working hard we can
C.Only we can by working hard
D.Only by working hard can we
简述尿液检验中常用的几种防腐剂的用途和用量。