缺铁性贫血最敏感或最可靠的检验方法是（）。

A.血清铁降低

B.血清总铁结合力降低

C.红细胞数下降

D.血色素下降

E.血清铁蛋白降低

---Bob’s___ the branches from the tree. Go and _____ for firewood. Bill!

---Do you think I’m really     for his kind of work?

A．cut away; cut it up; cut through

B．cut off; cut it down; cut out

C．cut away; cut it up; cut out

D．cut off; cut it down; cut out