题目

______ is known to all is that while driving drivers should keep an eye out for road signs, on which are words or symbols giving directions or other traffic instructions. A. What      B. As        C. It         D. Which 答案：A已知，是函数的两个相邻的零点.（1）求；（2）若对任意，都有，求实数的取值范围．（3）若关于的方程在上有两个不同的解，求实数的取值范围．