Schilling试验是检测（）
A.叶酸吸收障碍
B.维生素B12吸收障碍
C.叶酸排泄障碍
D.维生素B12排泄障碍
参考答案：B
The teachers are strict us and we are strict _ our homework. [ ]
A. with;with
B. in;in
C. with;in
D. in;with
