(来学网)卵子受精后第几天分裂成16个细胞组成的实心团块称为桑葚胚,于第几天早期囊胚进入子宫腔,在受精后第几天囊胚开始着床
  • A.
    (来学网)2,3,4~5
  • B.
    (来学网)3,4,6~7
  • C.
    (来学网)4,5,7~8
  • D.
    (来学网)5,6,8~9
  • E.
    (来学网)6,7,8~9