答案：A
— Does your leg still ____?
— Yes. It ____ a lot when I am trying to move it a bit. [ ]
A. hurt; hurts
B. wound; wounds
C. injure; injures
D. pain; pains
设f(x)有连续导数，且f(0)=0，f’(0)≠0，。当x→0时，F’(x)与xk是同阶无穷小量，则k=（）。
A．1
B．2
C．3
D．4
。当x→0时，F’(x)与xk是同阶无穷小量，则k=（）。