几个旁观者站在那里看着事故的发生，但没有一个人上前帮忙。

Several ___bystanders stood there watching the accident but no one stepped forward to help.

车祸发生时，几个路过的旁观者立即拨打了急救电话。

When the accident happened, several passing ___bystanders immediately called for an ambulance.