To her joy, Della earned first the trust of her students and then of her colleagues.
A. that
B. one
C. ones
D. those
网友回答
(答案→)A. that
B. one
C. ones
D. those
解析：考查代词：句意：使她高兴的是，德拉先得到学生的信任，然后得到同事的信任。这里需要代词指代trust，that是特指前面的可数名词单数或是不可数名词，而且后面有后置定语，one是泛指前面的可数名词单数，ones是泛指前面的可数名词复数，those特指前面的可数名词复数，而且后面有后置定语，所以选A。