逆行性牙髓炎属于（）
A．侵袭性牙周炎
B．艾滋病
C．慢性牙周旋
D．牙周-牙髓联合病变
E．牙龈炎
参考答案：D
下列省级行政单位中，位于黑河—腾冲线以西的是
A．A
B．B
C．C
D．D
Few of them came to the city, ?[ ]
A. don't they
B. do they
C. didn't they
D. did they
