题目

若≥a2 a对任意的x∈（0，+∞）恒成立，则实数a的取值范围是 A．a≤-2或a≥1         B．a≤-1或a≥2           C．-2≤a≤1               D．-1≤a≤2 答案：D— My father has a very sore throat .— .A.It’s too bad .B.Sorry to hear that .C.Very well .D.Congratulations