脐以下的部位称为（）
A.胃脘
B.少腹
C.小腹
D.大腹
E.心下
参考答案：C
If nature does not provide man with the necessary material, it is the laboratory ____ he will turn to for it. [ ]
A. where
B. that
C. which
D. what
渗透定价法
