________ he still paused uncertain, he became aware that the driver was looking closely in from the street at this unusual scene.

A．While

B．As

C．Since

D．Because

住房问题既是（）问题也是发展问题，关系千家万户切身利益，关系人民安居乐业，关系经济社会发展全局，关系社会和谐稳定。

A、经济

B、社会

C、民生