Trees Keep the air clean.这句话的意思

Trees Keep the air clean.这句话的意思 keep the air frsh 六年级上册英语练习册练习题解答（说理由）1.the air _____the balloon high in the sky.A keep B make C keeps2.trees _____the air cleanA keeps B keeping C keep翻译句子：what's the function of the air to the things the sky?Can you 把以下句子变为一般疑问句和反问句：Trees help us in many ways.Trees keep the air cool and clean.They take in harmful gasses from they air.They are major fighters against air pollution.I know trees make our lives more convenient.Many o you'd better close the window and () the cold air ()A.keep;on B.keep;out C.keep;up Dkeep;back ___can help the tree grow.And trees help clean the___.A.Sunshine,air.B.Sunshines,air.C.Sunshine,airs.D.Sunshines,airs. To improve the ＿they planted more trees and grass A.environmend B.water C.air D.land到底是什么？ The air is c( ) Why do people plant trees every year?——(keep) our air clean ( )Please ___the door open.The air in the room is not good.A.keep B.take C.let D.help would you please keep the window___?let the fresh air in.A open B opening C opened D to open keep the window ____ to let the fresh air in . A.close B.closed C.from opening D.open Trees and piants can make the air ciean .和 They can keep the water from fiowing away.和 they canstop the wind from biowing up sand and earth.谁帮我翻一下这四句呢 Trees and piants can make the air ciean . 和 They can keep the water from fiowing away.和 they canstop the wind from biowing up sand and earth. 谁帮我翻一下这四句呢 by planting more trees ,we can ________ the number of greenhouse gases in the air.A .bring B.bring down C.go up D .go down尽快! we should keep the air ___ ___ ___ (清新) 水树奈奈keep your hands in the air中文歌词谁有水树奈奈keep your hands in the air的中文歌词? If there are _ trees,the air in our city will be _ fresher.A.less;more B.more;more C.more;much D.much;more