A：
B：（v1＋v2）/2
C：2v1v2/（v1＋v2）
D：v1v2/（v1－v2）
句型转换She is fourteen.. (对划线部分提问) ____ is she ?It is a bus.(改为复数形式) They ____ .It’s my ruler.(改为否定句)It __________ my __________.____ He has a big nose. (变为一般疑问句) _________ he __________ a big nose?____ This is my schoolbag. (改为同义句)This schoolbag is __________.____
________ are the peaches? Seven yuan.
