He tried to deal with the increasing burden of his work,but he finally _____and had to take a complete

rest.   [ ]

A. broke off      

B. broke away        

C. broke out           

 D. broke down

患者初戴全口义齿，主诉上颌左侧压痛，不能咬合。查：全口义齿固位好，基托伸展合适，咬合接触良好，相对于臣处黏膜上有一小出血点，余之未见异常。造成疼痛的原因是（）

A.人工牙有早接触

B.基托组织面有树脂小瘤

C.印模不准确

D.模型不准确

E.咬合不稳定