根据对话内容从方框中选择能填入空白处的最佳选项补全对话，其中有两项多余．
A：Danny,who is your best Mend?
B：My best friend is Mike．
A：____
B：He is tall and has a round face with short black hair.
A：____
B：He likes playing football and basketball．
A：How long have you been friends?
B：____
A：Is he an ice boy?
B：____
A：Can I make friends with him?
B：____
A：That's great!
A．Of course you can! B．What's his hobby? C．Since ten years ago． D．Where does he come from? E．Yes,he often helps others． F．What does he look like? G．How did you know each other? |
CO（g）+H2O（g）在一定温度下，反应平衡时有80%的氢气变成水，且c(CO2)×c(H2)=c(CO)×c(H2O)，则原混合气体中CO2和H2分子数之比是：