_____ that it was sold out when it came out.

A．So was her successful book

B．So successful was her book

C．So her book was successful

D．So successful her book was

由于服务的（），使得作为物业服务消费者的业主，难以像有形产品的消费者那样感到物业服务的真实存在，对于服务消费意识较薄弱的部分业主，难以产生物有所值的感觉。

A.无形性

B.即时性

C.长期性

D.综合性