题目

J．K.Rowling is the writer of Harry Potter, which is now one of ______sellers in the world. She was born in Britain on July 31st, 1965. She had one sister who was two years younger than her. Both girls liked ______ to their father's bedtime stories. They especially loved stories about magic. Rowling wrote her first story______the age of six.On a long train trip in 1990, an idea came to her. She wanted to write about a boy who had magic but he didn't know it. In 1992, Rowling began______ the first Harry Potter book for young______. It appeared in June, 1997. The book was a great success. And t 如图，在△ABC中，已知AB=AC=4，BC=，且△ABC≌△DEF，将△DEF与△ABC重合在一起，△ABC不动，△DEF运动，并满足：点E在边BC上沿B到C的方向运动，且DE始终经过点A，EF与AC交于M点。探究：在△DEF运动过程中，重叠部分能否构成等腰三角形？若能，求出△AEM的面积；若不能，请说明理由。