－What would you like for your birthday ? What about an MP5?

－Oh, to tell the truth, I ______ have an I-Pad than an MP5.

A．prefer

B．prefer to

C．had better

D．would rather

免疫球蛋白中相对分子质量最大的是（）

A.IgA

B.IgM

C.IgD

D.IgG

E.IgE