1.Water  pollute => pollution in the lake has made the fish die.

      A         B                             C                       D.

2. Factories  don’t => won't dump waste into rivers if the government fines them heavily. 

            A                 B                  C                                                                 D

3.The earthquake occurred at midday when many people had had => were having lunch.

                                    A             B                  C                    D

4.Hundreds of houses destroyed => were destroyed after a tornado hit the small town of Texas.