"蜗牛胃"和"葫芦胃"的病理基础是（）
A.痉挛性改变
B.肿瘤压迫
C.瘢痕性改变
D.正常蠕动波
E.以上都不是
参考答案：C
Before he was arrested, he had taken _______ one-month holiday, and stayed in the country with ________ 18-year-old girl, one of his students.
A．a, a
B．an, an
C．a, an
D．an, a
关于铁代谢，哪项是正确的（）
A.缺铁时正常肠黏膜对铁吸收减少
B.血清铁一般是亚铁离子
C.维生素C能把食物中铁游离化
D.铁主要在空肠下段吸收
E.在肠黏膜内能合成铁蛋白
