题目

阅读下面的短文，然后按照要求写一篇120词左右的英语短文。 For long, there was a little boy with a bad temper. His father gave him a bag of nails and told him that every time he lost his temper, he would hammer a nail in the back fence. The first day the boy had driven 37 nails into the fence. Then it gradually dwindled(逐渐减少) down. He discovered it was easier to hold his temper than to drive those nails into the fence. Finally the day came when the boy didn't lose his temper at all. He told his father about it and the father suggested that the boy now pull out on 如果一个椭圆的长轴长是短轴长的两倍,那么这个椭圆的离心率为       .        .        .         .