题目

口语交际 A:根据对话内容从方框内所给的选项中选出最佳答案，使对话完整，符合逻辑，句义通顺。注意：有多余选项。 A: Excuse me,  1  B: Yes, and you are……? A:  2  . This is my membership card. Would you please show me your passport? B: OK.  3  A: Welcome to Beijing, Miss White. I am so glad that you are the first guest I have received. B: Thank you, Miss Chen.  4   A: Let me help you with your suitcase. Our car is waiting for us just at the entrance.  5   B: Thank you very much for your good service. A: It’s a pleasure. A. Who a如图，已知点E,F分别是□ABCD的边BC,AD上的中点，且∠BAC=90°．（1）求证：四边形AECF是菱形；（2）若∠B=30°，BC=10，求菱形AECF面积．