磨除双尖牙畸形中央尖时意外露髓（）
A.直接盖髓术
B.间接盖髓术
C.牙髓摘除术
D.牙髓切断术
E.根管治疗术
参考答案：A
In his effort to prevent his company from _____, he worked to his limit, thus _____. [ ]
A. breaking down; breaking down his health
B. closing down; broke down his health
C. closing down; his health broke down
D. breaking down; his health breaking down
通常企业总是千方百计降低人员费用来增加( )。
A．产值 B．收入 C．利润 D．企业收益
