制冷剂回收/净化/加注设备与制冷装置连接前，应进行制冷剂类型的鉴别和纯度的检测。

A.建设单位
B.监理单位
C.勘测单位
D.城建单位

A．People from four different areas can have different personalities and accents.
B．People in the four countries speak the same language.
C．The U.K. is interesting because the people from the four areas belong to four different parties.