to-and-fro

They travel to and fro between London and Paris.

他们奔走于伦敦和巴黎之间。

Wilkie watched the to and fro of their dancing.

威尔基看着他们回回地跳舞。

Pat rolled the trolley to and fro.

帕特回推着手推车。

Those boats are prepared for waftage to and fro.

那些船舶是准备用回运送货物的。