单选题 A group of neighbors ______ the fire burning in the building by the time emergency responders arrived on the scene.
  • (A) had extinguished
  • (B) extinguished
  • (C) extinguishes
  • (D) will have extinguished


【正确答案】 A
【答案解析】[语法] 过去完成时
[错误答案] 语意上应该是说在救援部队到达现场之前，已经扑灭了火，所以要使用比过去时态更早的过去完成时态。