--I once got lost during my first visit to Beijing.

-- Oh, did you? You ____ me as your guide.

A．might have asked

B．could ask

C．would have asked

D．would ask

下列有关PrP的描述，错误的是：（）

A.可致海绵状脑病

B.有两种异构体

C.含有核酸

D.需要特殊消毒才能灭活