在当时,那真是一件不得不忍受的苦事.It was really a bitter pill to swallow at that time.批改试卷的确是个苦事.Marking examination papers is a real grind.在当时,那真是一件“不得”不忍受的苦事.It was really bitter pill to swallow at that time....

“苦事”的英语可以翻译为：hard job ...