(POLLUTE) HUMAN BEINGS ARE DESTROYING THE AIR BY ADDING ________ T...

37. - TUYEN TAP DE THI ANH VAN 11 CO DAP AN HOC KY II 45 PHUT LOP
TUYEN TAP DE THI ANH VAN 11 CO DAP AN HOC KY II 45 PHUT LOP
37. (pollute) Human beings are destroying the air by adding ________ to it.