英语单句改错急.在考试.More and more.People are concerned about the way

英语单句改错急.在考试.
More and more.People are concerned about the way which the environment is being desyroyed..2.Standing on the bank l saw some tiny fish swim round in circles.3.On hearing that he had return back to the usa ,his mother smiled happily 4 .The olympic games are help each four years