听音填空，完成下列短文
We all know the air____us____．____makes the air dirty and it makes us unhealthy．Rubbish makes the land and water dirty．The dirty land and water makes us unhealthy and ____too．Trees make the____ ____and beautiful．Trees also give us delicious fruit and useful____．We should keep the air clean and ____throwing rubbish into rivers, lakes or seas．We should plant ____trees．
