题目

     We were on tour a few summers ago, driving through Chicago, when right outside of the city, we got pulled over. A middle-aged policeman came up to the car and was really being troublesome at first. Lecturing us, he said, You were speeding. Where are you going in such a hurry? Our guitarist, Tim, told him that we were on our way to Wisconsin to play a show. His way towards us totally changed. He asked, Oh, so you boys are in a band (乐队)? We told him that we were. He then asked all the usual band questions about the type of music we played, and how long we had been at it. Suddenly, 如图，在△ABC和△CDE中，∠B=∠D=90°，C为线段BD上一点，且AC⊥CE．AB=3，DE=2，BC=6．求CD的长．