To her joy, Della earned first the trust of her students and then of her colleagues.A. o

网友回答

A. one
B. ones
C. those
(答案→)D. that
解析：考查指示代词。句意：让她高兴的是，Della先赢得了她的学生的信任，接着赢得了她的同事的（信任）。one泛指可数名词，意为“一个”；ones“一些”；those指代复数；that指代不可数名词。这里指代trust，trust是不可数名词，应该用that。故选D。