名词：back-and-forth
back and forth英英释义
Adverb
moving from one place to another and back again;

"he traveled back and forth between Los Angeles and New York"
"the treetops whipped to and fro in a frightening manner"
"the old man just sat on the porch and rocked back and forth all day"

back and forth近义词
backward and forward
to and fro

back and forth