A:which I think i
B:which I think it i
C:which I think it
D:I think which i
——David, could you tell me _________?——Every four years.
在细胞有丝分裂的过程中, DNA 分子数目相同而染色体数目不同的时期是()
托勒密认为所有的日月星辰都是围绕着太阳转动的。