They are living with their parents for the moment because their own house ____.

A．is being rebuilt

B．has been rebuilt

C．is rebuilt

D．has rebuilt

 Na₂O和Na₂O₂的下列叙述中正确的是                      (    )

A．Na₂O比Na₂O₂稳定

B．均可与水反应

C．均可与CO₂发生化合反应

D．均是典型的碱性氧化物