-- Your uncle speaks good English. Who taught him?

-- ________, he learned it by himself.

A．To begin with

B．To my surprise

C．To be honest

D．Thanks to

可用于外周造血干细胞的动员的是（）

A.红细胞生成素

B.α干扰素

C.白介素2

D.粒细胞集落刺激因子（G-CSF.

E.白介素11