walk down the stairs的stairs为什么不能用ladders

walk down the stairs的stairs为什么不能用ladders walk down stairs quickly walk down the stairs quickly.） she rushed down the stairs The apple are falling down the stairs的意思 The apples are f___ down the stairs down,are ,the,falling,apples,stairs. Don't take the lift,____(walk)down the stairs quickly. we walk quickly down stairs must the 怎么连词成句? or just heip them walk down their stairs some students may run down the stairs 对run down the stairs提问 I went down stairs quickly.为什么quickly要放在最后,不放在动词前?