Trees Keep the air clean.这句话的意思

Trees Keep the air clean.这句话的意思 help,air,trees,the,keep,clean连词成句句号 trees help keep the air clean help后可以直接跟keep吗 lark in the clean air 的意思 Trees can help___the air and keep it ___ .A.clean;clean.clea Trees cool the air as well as clean it.的同义句,越多越好,求高手回答. I'm outdoors in clean air. 请帮忙解答下这句话的意思. Trees not only cool the air but also clean it. 这句话的英文回答In the air fresh or clean in your city? make the forest clean&keep the forest clean 中,make和keep的意思,两 Why do people plant trees every year?——(keep) our air clean planting tree can help( )the air clean 是用keep 的什么时态?