生命是美好的,人类的新生命开始于( )
A:卵细胞
B:精子
C:受精卵
D:新生儿
____ He's my brother.
____ Who's that boy?
____ Yes, she is.
____ Is she your mother?
____ No, he isn't. He's my teacher.
____ Is he your father?