肛瘘手术治疗的关键是()
A.切除肛管周围疤痕组织
B.切开瘘管壁,敞开外流
C.避免切断肛管外括约肌皮下部和浅部
D.切开肛管直肠环
E.正确找到内口,将内口切开、切除
参考答案:E
某项队列研究得出的相对危险度为2.6,95%的可信区间为1.7~3.4,下列哪种说法不正确()
A.率差为1.7
B.暴露与疾病的关联为正关联
C.暴露组的发病危险比对照组高
D.暴露组的发病危险是对照组的2.6倍
E.该暴露因素是疾病的危险因素
A computer generates non-zero numbers for the figure above so that the product of the numbers along any vertical column is equal to the product of the numbers in any horizontal row. What number does s represent (1) u equals 6. (2) t equals 2.