1. They might have found a better hotel if they ________ a few more kilometers. 

     A. drove               B. would drive    C. were to drive  D. had driven  

2. If the new safety system ________ to use, the accident would never have happened.

     A. had been put        B. were put       C. should be put  D. would be put

3. If we ________ the flight yesterday, we would be enjoying our holiday on the beach now.

     A. had caught                            B. caught        

     C. have caught                           D. would catch