随着通讯市场竞争日益激烈，某通讯公司的手机市话费按原标准每分钟降低了a元后，第二次下调了25%，现在的收费标准是每分钟6元，那么，原收费标准为每分钟（）元。

A.A

B.B

C.C

D.D

He______the leader of the Model Group in our factory.

A．has just been appointed

B．has just appointed
C．just appointed


D．has just being appointed