on/from the sidelines 

sideline /'sa?dla?n/ n. 球場(chǎng)邊線；副業(yè)；局外人的觀點(diǎn)

If you are on the sidelines or do something from the sidelines, you are not actively involved in something.

旁觀;不參與

He has just stood on the sidelines up to now and let the situation get worse.

他僅僅是置身局外，任憑事態(tài)惡化。

She could only watch from the sidelines as her brother's health deteriorated.

她只能眼睜睜地看著弟弟的身體垮下去。

（素材來自網(wǎng)絡(luò)，如有侵權(quán)請(qǐng)聯(lián)系刪除）