题目

. ----Has Tom already finished his new story? ----I have no idea. He ______ it last month. A. had written               B. was writing                     C. would write                     D. wrote 答案：B在△ABC中，D，E分别为AB，AC上的点，且DE∥BC，BE，CD交于点O，则图中共有22对相似三角形．