Skating is Bob's favorite sport. He         goes skating in winter.        [ ]

A. usually                

B. never        

C. hardly                

D. seldom

便时出血、肛缘突起圆形肿块、疼痛

A．肛门周围脓肿
B．直肠息肉
C．肛裂
D．血栓性外痔
E．肛管癌