All her hard work in the end and she finally passed the examA. paid backB. paid offC. b

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