全口义齿就位困难的原因有（）
A.倒凹过大
B.义齿变形
C.义齿戴错
D.倒凹过小
E.粘膜过厚
参考答案：A, B, C
He broke his leg last week. The doctor asked him ________ in bed for two weeks. [ ]
A. to stay
B. stayed
C. staying
D. stays
实施卫生行政许可，应当遵循法定的（）和程序
A.权限
B.范围
C.条件
D.规范
E.标准
