—Shall I take you home after school?

—No, thanks, Father will  _______on his way home.

A．wake me up

B．pick me up

C．let me down

D．help me out

受精卵形成后不断进行分裂，发育成胚泡后移到并植入______进一步分裂和分化．怀孕后______周左右发育形成胎儿，胎儿通过______、脐带从母体中获得所需要的营养物质．