她发誓再也不会离开孩子们了。

She ___vowed that she would never leave the children again.

我已经发誓再也不去那里了。

I've ___vowed never to go there again.

在那次事件之后，他发誓再也不踏进体育场一步。

After that episode, he ___vowed that he would never set foot in a stadium again.