—How about the book you are reading?—Good indeed. It many problems we have come across in our study.
I don't junk food. It's bad for your health.
如图，在△ABC中，BC＞AC，点D在BC上，且DC=AC，∠ACB的平分线CE交AD于E，点F是AB的中点，则S△AEF：S四边形BDEF为
