"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"
双语例句
She spent hours every day in the tower room, reading and rereading. 她每天都要在这个塔室里消磨好几个小时，读着，反复地读着。
