题目

If you have the opportunity to visit some places in New Zealand, then the list below is our recommendation.Fiordland National ParkThis park is part of the South Westland World Heritage Area and is New Zealand’s largest national park and one of the largest in the world. The scenery in Fiordland is nothing short of extremely beautiful, with steep mountains, wild waterfalls, and abundant rain forests. Being able to come back and forth in its deep bay attracts most of the visitors.The area has some of the world’s greatest walks including the world famous Milford Track, which was described as t已知集合A=[2，log2t]，集合B={x|x2-8x+12≤0}，x，t∈R，且A⊆B．（1）对于区间[a，b]，定义此区间的“长度”为b-a，若A的区间“长度”为1，试求t的值．（2）某个函数f（x）的值域是B，且f（x）∈A的概率不小于，试确定t的取值范围．