A:the local government care
B:does the local government care
C:doesn't the local government care
D:cares the local government
矿井里的升降机,由静止开始匀加速上升,经5s速度达到6m/s后,又以此速度匀速度上升10s,然后匀减速上升,又经10s停在井口.求矿井的深度.
①细胞代谢 ②细胞增殖、分化 ③细胞内基因的传递和改变.