---How about a visit to Hongkong Disneyland?

---___________  I have been looking forward to it for a long time．

A．I agree it.

B．That’s right.

C．I don’t mind.

D．Why not?

在一个种群中基因型为AA的个体占70%，Aa的个体占20%o，aa的个体占10%。A基因和a基因的基因频率分别是[ ]

A．70%、30%

B．50%、50%

C．90%、10%

D．80%、20%