单选题 These machines have {{U}}been idle{{/U}} for the past months.
  • A. been working well
  • B. been working badly
  • C. not been in service
  • D. not been running at all
【正确答案】 D
【答案解析】[解析] not been running at all是指“完全不运转，闲置的”。与本题划线词been idle的意思接近。been working well“运转良好”；been working badly“运转不良”；not been in sevice“没有服役，没被使用”。