【题目】 They kept trying, and their efforts finally _____. They got enough money to _____ their debt.
A. are paid off; pay back B. paid off; pay off
C. are paid for; pay back D. paid back; pay off
在线课程【答案】B
【解析】
试题分析：考查动词短语。句意：他们继续努力，他的努力最终得到回报，他们有足够的钱来偿还债务。Pay off 得到回到，pay back还清，故选B项；
考点 : 考查动词短语