the air travels only 240 kilometers away from the earth其中travel是什么意思?为什么不能用reachs?顺便问一下关于travel的词组短语以及用法~

the air travels only 240 kilometers away from the earth其中travel是什么意思?为什么不能用reachs?顺便问一下关于travel的词组短语以及用法~ father travels by air ( )in the family.a the most ofen b the oftenest Sound travels in the form(形式)of _.A.bones B.air C.waves D.voice Only the earth has ) environment with air. Father travels by air ___ in the family.A.oftenest B.the most often C.oftener D.the oftenest sound travels through air的中文意思 If only we could bottle the fresh air.翻译 sound travels at 340 meters per second in air.travels 为什么用at? 英语翻译Not only is the air heavy with culture,but also with Japanese precision and order.air：气氛,氛围 ...if we did not have air ,there would be no sound because sound travels through air对划线部分提问sound because sound travels through air提问 the air reaches only 240 kilometers away from the earth 翻译成中文 The earth travels around the s------. Light travels at a speed which is about a million times faster than the speed of sound.In one second,light travels about 300,000km.But sound travels only 344m.You can get some idea of this difference by watching the start of a race.If you stand some 英语翻译Light travels in a traight line because it is the only paths that always constructively interferes with itself.all other paths on average sum to zero Not only the air but also the water here has been polluted.(改为否定句)____ the air _____the water here has been polluted 英语翻译The man often travels ______ ______. nothing in the world travels faster than he often travels ___ the summer vacation