构成传染病流行过程的基本单位是
A．疫点
B．疫区
C．疫源地
D．家庭
E．社团
参考答案：C
The injured man _______ to hospital by a driver yesterday. [ ]
A. takes
B. took
C. is taken
D. was taken
肿瘤的三级预防中属于二级预防的内容是（）
A.病因预防
B.早发现，早治疗
C.康复预防
D.减少癌症的发病率
E.提高生存质量，减少痛苦
