_________ knows anything about him because he never tells us ________ about him.
A:Nobody; something
B:Somebody; nothing
C:Anybody; something
D:Nobody; anything
一架飞机从北京出发,沿经线一直向北飞行,最终能到达( )
受精卵发育成为胚胎所需要的营养物质最初来自于( )