题目

    When you put down your pens at the end of the college entrance exam, 12 hard years of study will have come to an end. Forget your studies for a while. It’s time to enjoy yourself. There are many ways to celebrate this special month of graduation. You can have photos taken with your classmates and teachers, or dine out together and exchange gifts. High school students in western countries as the United States and Canada usually have a prom to mark their graduation. It’s to mark the time kids turn into young men and women. After the prom, teenagers either go to college or find a job.观察一组数：-3，-15，-35，-63，______，…根据规律解决下列问题：（1）______中应填什么数？（2）第100个数是多少？（3）第n个数是多少？