她保持直立的姿势让背部更舒服。

She maintained an upright ___stance to keep her back comfortable.

她在社交媒体上明确表达了自己对环保议题的立场。

She clearly stated her ___stance on environmental issues on social media.

他在辩论中采取了强硬立场。

He took a firm ___stance during the debate.