她摇着头，左右摆动表示不同意。

She shook her head ___side-to-side to show disagreement.

将这两张图片并排放在一起，方便我们比较。

Put these two pictures ___side-to-side so we can compare them easily.

她在辩论中来回摇摆，让观众难以确定她的立场。

Her ___side-to-side debating style made it difficult for the audience to pin down her position.