He was a stranger in this town, so the local people didn’t know _______.

A．how could they make friends with him

B．how they could make friends with him

C．how can they make friends with him

D．how they can make friends with him

利用金属活性的不同，可以采取不同的冶炼方法冶炼金属。下列反应所描述的冶炼方法不可能实现的是[ ]

A．2Al₂O₃(熔融)4Al＋3O₂↑

B．Fe₂O₃＋3CO2Fe＋3CO₂

C．Fe＋CuSO₄==FeSO₄＋Cu

D．2KCl(水溶液)2K＋Cl₂↑