填空题 His recommendation that Air Force investigates the UFO sighting was approved by the commission and referred to the appropriate.
  • A. investigates
  • B. was
  • C. by the commission
  • D. to


  • 1、
【正确答案】 1、A应改为(should)investigate。    
【答案解析】[解析] 同位语从句修饰recommendation，从句用虚拟语气。