(  )1. That's wasteful to throw away waste paper.
           A          B             C               D
(  )2. Both Tony and Sam has been to the Great Wall.  
          A              B            C   D
(  )3. Everyone in the green school do something to help protect the environment.
                                                       A     B           C         D
(  )4. Those small factories cause too many pollution every day.
                                           A      B      C      D
(  )5. We should do our best to stop the factories from pollute the air.  
                           A                    B                         C     D