A:①④
B:①②
C:②③
D:③④
如图,人的造血干细胞产生血细胞的过程在生物学上称为( )
The girl's information(信息)
First name: _____________
Last name ___________
School: No.6 Middle School
Class: _______, Grade: 7
Phone number: 82506372
School ID card number: ___________
Favorite color: ____________