任务型阅读

    Have you taken a plane? Have you thought about the ways to survive(生存) in a plane crash(坠机)? Here are some tips for you. ____.

    ____ .The key to survive on planes is how quickly you can get out. So it's best to get seats as close as possible to a door. Or try to sit in the back of the plane because passengers in the back seats are safer than those in the front.

    ____ .First of all, read the safety information card and listen to the safety speech carefully. Every type of plane has different safety instructions. If you're sitting near a door, make sure you know how to open it if you need to. What's more, don't forget to keep your seat belt fastened(系牢) .

    ____.When there is a fire, breathing smoke in is one of the main causes of death. So cover your nose and mouth with a cloth to avoid it.

    ____.Don't be too nervous and try to keep a cool head all the time. Remember that even in the worst situation, you still have a chance to be safe.

阅读下列材料

材料一：……以牙还牙，以眼还眼……“如果理发师不经奴隶主人许可，就把属于它的奴隶头上的奴隶标记剃掉，理发师的手就要被砍掉。”

材料二：在农村，种姓制度则比较根深蒂固。人们依然可以根据衣着、举止、语言用词甚至头饰来判断人们的种姓，而高种姓的人与低种姓的人来往不多。

材料三：印度种姓制度这颗参天大树虽然开始腐烂崩溃，但倒下的速度却十分缓慢。现实情况也的确如此。在目前印度政治和经济生活中，高种姓的人仍掌握着国家经济命迈和行政大权。

请回答：

若函数f（x）=（a﹣1）^x在（﹣∞，+∞）上单调递增，则实数a的取值范围是____．