单选题 The firm should make a substantial profit ______ satisfactory labor relations are maintained.
  • A. in case
  • B. with the purpose that
  • C. provided that
  • D. even if
【正确答案】 C
【答案解析】[解析] 四个选项都是起从属连词作用的词或短语，因此答题的关键是分析前后两个句子的逻辑关系。in case和with the purpose that引导目的状语从句；even if引导让步从句；而provided that引导条件从句，正好符合该句句意。