问题
选择题
Mary was always singing high praise for her role in the office, _______，of course,made her colleagues unhappy.
A．who
B．which
C．this
D．what
答案
B
填空处是指前面整个句子所述的内容，为非限制性定语从句，用which引导。句意为“玛丽总在赞扬她在办公室里的作用，这当然使她的同事们不高兴了”。