moving up and down in time with the terrain

what goes up and down the stairs without moving? moving up and down in time with the terrain What can go up and come down without moving? everybody moving up and down帮我翻译 Buses and cars are moving up and down the street.的翻译. I saw the kite up and down 中 up and down 是什么词性,修饰什么? we wen up directly high in the air and right back down .moving around very little翻译一下 up and down翻译 up and down? up and down 翻译 jump up and down jumped up and down I've been up and down (uh, what) 怎樣翻譯? I've been up and down with a virus through every up and down I'll always be around. The train was moving.I heard my good friend's voice _ in the wind.A.came up B.died down C.got down when i lay down they stand up,and when i stand up they lay down.谜底是什么? I like watching dolphins_____A.to junmp up and down B.jump un and downC.junmps up and downD.jumped up and down选择并说明为什么?