Liu Kai is my classmate. He is a good student and always ready to help the others. One day on his way school, he saw a little girl crosses the road. A car was coming towards to her quickly and the girl was so frightened to move. The car near hit her. Just then Liu Kai rushed up to her and caught her on the arm. The little girl was saved. She tells him where she lived, but he took her home. When Liu Kai hurried into the classroom, the teacher has already begun his lessons. He told the teacher why he was late. He was then praised for which he had done.

下列选项中3个月是（）

A.固定修复的最佳时机是拔牙后

B.前牙创伤牙折伴牙周膜撕裂伤，根管治疗后到桩冠修复时需时

C.上颌种植修复时最佳时间是拔牙后

D.进行可摘义齿修复至少应在拔牙后

E.下颌种植修复的最佳时间是在拔牙后