People should be good because that cultivates people to throw down the river it might not have been the best cultivates so do not know how to throw it into the river is something that should not be made.
People should be cultivating good because people are dumping garbage into the river, it could not have been better awareness so that the waste into the river is something that should not be done.
People should be to cultivate good conscience, because people still waste into the river, that may not be cultivate good conscience makes know that waste into the river is what should not do.