题目

One evening. Li Hua was watching TV when his mother76           was busy preparing for supper. Li Hua was so hungry77           that he began to complain about his mother’s slowness. 78           At that moment, the telephone rang. It was friend of79           his mother’s. He told Li Hua that day is his 70           mother’s birthday and he hoped his mother a happy81           birthday. What a shame! Li Hua had forgotten all 82           his mother. He got deep shocked. It’s not until83           then that下列有关细胞分裂和分化的叙述，错误的是（　　）A．细胞分裂过程中，细胞内变化最明显的结构是细胞核B．癌细胞分裂产生的新细胞染色体数目不改变C．癌细胞分裂产生的新细胞基因发生了改变D．利用干细胞可成功修复患者受损神经细胞的依据是细胞分化原理