The house is finished at last. All their hard work has .A. paid backB. paid off C. paid up

问题补充：

The house is finished at last. All their hard work has .

A. paid back

B. paid off

C. paid up

D. paid for

答案：

A. paid back

(答案→)B. paid off

C. paid up

D. paid for

解析：短语辨析。A归还；偿还；B付清；努力得到回报；集合句意可知B正确。句意：房子终于建好了。所有的努力工作都得到了回报。