单选题 Doctors and researchers have to keep themselves ______ on the latest developments in their sphere of study.
  • A. convinced
  • B. isolated
  • C. humiliated
  • D. updated
【正确答案】 D
【答案解析】convince：使……相信(接of)；isolate：隔离，孤立；humiliate：羞辱，侮辱；update：更新，把最新情况通告。