问题补充:
In order to the debt, the couple has worked hard for years with little food and only a small room to live in and never a moments rest.
A. pay for
B. pay back
C. pay
D. return back
答案:
A. pay for
(答案→)B. pay back
C. pay
D. return back
解析:pay back表“偿还”,pay for仅表“付钱”。