可刺激骨髓巨核细胞分化、成熟和血小板产生的细胞因子是()

A．IL-7

B．IL-5

C．TPO

D．IL-6

E．IL-11

（）is halfway between the forward and after perpendiculars and is reference point for vessel construction.

A.Half length

B.Mid-body

C.Center line

D.Amidships