I drove back down the highway at normal speed.我以正常车速沿公路返回。I'll take you back down to the valley.我会带你返回下面的山谷里。He freewheeled back down the course.他沿原赛道滑了下去。...

back down的音标：back down的英式发音音标为：[bæk daun]back down的美式发音音标为：[bæk daʊn]...

退让，退回去，撤销（要求等）...