查询结果:

adv. 来回,往复 

例:
to rock to and fro 轻轻摇来摇去
Small boats busied to and fro.小船来来往往地穿梭。
She held the baby in her arms and rocked her to and fro.她把婴儿抱在怀里来回摇晃。
They travel to and fro between London and Paris.他们奔走于伦敦和巴黎之间。