Peopleinsomeareasarecuttingdowntreesforhousebuilding.Treesbyhumanbeingsforhousebuilding.arebeingcutdownAlotofrubbishispollutingtheocean.Peoplearekillingtheelephants.*现在进行时的被动语态火眼金睛表示主语是动作的承受者。ManystudentsstudyEnglish