He devoted most of his time to research, believing his hard work would ________ sooner or later．
A.put offB.take offC.turn offD.pay off在线课程D
本句意为“他投入了大量的时间做研究，他相信他的努力迟早会得到回报的”。put off意为“推迟”；take off意为“脱掉(衣服)，(飞机)起飞”；turn off意为“关掉(电视、电灯)”；pay off意为“成功、带来好结果”。