戴用上颌全口义齿的患者，静止时固位良好，咳嗽时义齿容易脱落，问题应该出在
A．主承托区B．副承托区C．缓冲区D．边缘封闭区E．后堤区
参考答案：E
_______you return those books to the library immediately, you will have to pay a fine.[ ]
A. Until
B. Unless
C. If
D. Provided
颈部正中包块，正中或正中旁瘘管间断性分泌物流出，应考虑为什么病怎样处理
