cross your arms/fingers/legs

to put one of your arms, fingers, or legs over the top of the other

交叉双臂/手指/双腿

She sat down and crossed her legs.

她坐下跷起了二郎腿。

Padma was sitting with her arms and legs crossed, one foot jiggling in time to the music.

帕德玛交叉着双臂，跷着二郎腿坐着，一只腿随着音乐的节拍抖动着。

Cross one’s fingers

to hope that things will happen in the way that you want them to

祈求好运

She has her exam this morning so cross your fingers.

今天上午她要考试，祝她好运吧。