Your efforts to develop good habits will later and it is well worth working hard to do s

问题补充：

Your efforts to develop good habits will later, and it is well worth working hard to do so.

A. pay off

B. pay back

C. pay for

D. pay up

答案：

(答案→)A. pay off

B. pay back

C. pay for

D. pay up

解析：句意：你养成好习惯的努力以后会得到回报，它是值得你这样努力工作的。pay off得到回报； pay back偿还； pay for付钱； pay up付清欠款。根据句意故选A。