Not until I began to work _____ how much time I had wasted.    [ ]

A. didn't I realize                                    

B. did I realize    

C. I didn't realize                                   

D. I realized

休眠期没有细胞分裂过程，则不能完成春化。如甘蓝种株上部芽开花而基部的休眠芽却形成小叶球。