After the new machine was introduced, the factory produced _____ in 2011 as the year before.

A．twice as many machines

B．twice many as machines

C．as twice many machines

D．as many machines twice

下列活动中，属于房地产服务业的有()。

A.房地产经纪

B.房地产咨询

C.物业管理

D.房地产评估

E.房地产开发