零售商业物业通常的类型包括( )。

A．区域购物中心

B．市级购物中心

C．地区购物商场

D．休闲度假中心

E．工业写字楼

The workers _____busily when the boss came to look for something she ______in the office.

A had worked, had left  B were working ; had left  C working ; had left  D had worked; left