问题补充：
All her hard work in the end, and she finally passed the exam．
A. paid back
B. paid off
C. brought out
D. brought off
答案：
A. paid back
(答案→)B. paid off
C. brought out
D. brought off
解析：考查词组意思，paid back意思“报答”， paid off意思“取得成功”， brought out意思“带出”，brought off意思“完成”，句子意思“经过她的刻苦学习最后取得了成功，她最后通过了考试”，所以选B
