----Is it my age __________ the boss minds?  

----I’m afraid not. He will consider __________ necessary to have an experienced assistant.

A．which; it

B．that; it

C．which; that

D．that; that

男性的基础代谢水平高于女性，原因主要是（）。

A.棕色脂肪组织含量多

B.瘦体质量大

C.体表面积大

D.劳动强度大

E.身材高