单选题 As an outstanding scholar, he has become ______ to the research team.
  • A. senior
  • B. junior
  • C. indispensable
  • D. independent
【正确答案】 C
【答案解析】本题考的是形容词的上下文搭配。indispensable不可缺少的，绝对必要的，根据题意，选项C为正确答案。