second,(the gas coming from the car engines and factories also make

　　environment polluted badly ).

　　the third reason actually is (the result of a growing population in

　　the world . everyday , so much litter and waste are poured out from

　　houses ,also pollute the environment ).

　　the significance for (controlling pollution ) noted that it's high

　　time that more effective measures should be taken .

　　therefore ,(new laws should be passed to limit the amount of pollutants

　　from factories . moreover ,in the households ,there is an obvious need

　　to reduce litter and waste . let's make our good efforts ,and the world

　　will be a safer place to live for us ).