bystander|bystanders

几个旁观者看到了车祸发生的过程。

Several ___bystanders saw the car accident happen.

几个旁观者拍下了车祸的全过程。

Several ___bystanders recorded the entire car accident.

几名旁观者拍摄了事故现场的视频。

Several ___bystanders recorded videos of the accident scene.