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。