Marywasalwayssinginghighpraiseofherroleintheoffice，

来源：语文精选馆 3.3W

Mary was always singing high praise of her role in the office，________ of course，made the others unhappy.

A．who B．which

C．this D．what

B　which引导非限制*定语从句，指整个主句所述内容。