解剖肛管是指：（）
A.直肠柱上缘至肛缘
B.肛管直肠环至肛缘
C.齿线至肛门缘
D.直肠柱上缘至肛白线
E.以上均不对
参考答案：C
全校1200名学生乘车去青少年宫参观，每辆车坐80名同学，需要几辆车？
There a concert organized for the disabled tonight. [ ]
A. is
B. will have
C. will be
D. is going to have
