题目

 -Wow! What a nice watch you have! -Well, it’s not ________. My grandparents bought it for my brother. A. mine            B. hers            C. yours         D. his 答案：AB，E，C，D分别是∠A两边的点，BC交DE于点O，且∠BCA=∠DEA，则图中相似三角形为  和 ，依据是 ．