下列地区属于人口稀少区的是（        ）

A．长江中下游平原

B．珠江三角洲

C．欧洲西部平原

D．亚马孙平原

It's really time I should go home, but I'm enjoying myself, so I ______ here a bit longer.

A．am staying

B．have stayed

C．stayed

D．stay