将代数式x2+4x-1化成（x+p）2+q的形式（ ）
A．（x-2）2+3 B．（x+2）2-4 C．（x+2）2-5 D．（x+2）2+4
答案：C
Miss Li ___as a secretary for five years in the company, and now she is general manager of it.
A．serves
B．served
C．has served
D．had served
属于胸椎的结构有（）
A.横突孔
B.横突助凹
C.齿突凹
E.棘突伸向后下方
E.上关节凹
