题目

. In the market, vegetables are sold by _______ kilogram, I mean, by _______ weight. A. the; 不填   B.不填; 不填 C. the; the      D.不填；the 答案：A 已知幂函数f(x)＝xα，当x>1时，恒有f(x)<x，则α的取值范围是(　　) A．(0,1)                                B．(－∞，1) C．(0，＋∞)                            D．(－∞，0)