treadmill
n
1 mill-wheel turned by the weight of people or animals treading on steps round its inside edge (formerly worked by prisoners as a punishment) （人力或畜力的）踏车（旧时用以惩治囚犯）.
2 (fig 比喻) tiring or monotonous routine work; drudgery 累人的或单调的例行工作; 繁重乏味的工作
I can't get off the office treadmill. 我无法摆脱单调的坐班工作.