若一个多项式的完全平方的结果为x2+mx+9,则m=( )
±6
妊娠3个月并甲亢的患者,不宜选择下列哪项检查
A.甲状腺B超
B.TSH测定
C.甲状腺摄131I率
D.TT3测定
E.TT4测定
At the railway station, the mother waved goodbye to her daughter until the train was _______. [ ]
A. out of sight
B. out of reach
C. out of order
D. out of place