下列眼外肌除哪条外，余均起自眶尖Zinn总腱环（）
A.下直肌
B.内直肌
C.上斜肌
D.下斜肌
E.上直肌
参考答案：D
家族性息肉首选（）
A.内镜下摘除
B.内镜下圈套电灼切除
C.开腹手术
D.肛门镜下显微手术
E.扩肛后拖出切除
—Your sister’s plan is not quite practical.Why not try to persuade her to give it up?
—My sister is very stubborn，so it is________to try to change her mind.
A．by chance
B．in vain
C．on purpose
D．for sure
