胎儿期的最初2周为______期，胎龄2～8周为_____期。8周至出生为______期。
参考答案：胚卵；胚胎；胎儿
According to media reports, the London stadium is other Olympic stadiums in terms of steel used.
A．as 75% light as
B．75% lighter as
C．75% lighter than
D．as light as 75%
水泥土挡墙
