多选题 For a long time, most doctors maintained that taking massive doses of vitamins was relatively harmless; now, however, some are warming that excessive dosages can be ______.
  • A. healthy
  • B. expensive
  • C. wasteful
  • D. toxic
  • E. inane
【正确答案】 D
【答案解析】[解析] however表示前后两句话是反义关系，过去认为过量的维他命没有危害(harmless)，可以推出现在认为过量的维他命是有害的。正确答案为D选项。