问题补充:
The house is finished at last. All their hard work has .
A. paid back
B. paid up
C. paid off
D. paid for
答案:
A. paid back
B. paid up
(答案→)C. paid off
D. paid for
解析:这题考查词组辨析:paid back报答,偿还,paid up全部还清,付清
paid off (努力)有回报,成功, paid for为…付钱,根据句意:这个房子最后完成了,所有的努力都没白费。选C。