你需要撤销对文档的那处更改。

You need to ___undo that change to the document.

如果你误删了一个段落，只需从“编辑”菜单撤销该操作即可。

If you delete a paragraph by mistake, just ___undo the action from the Edit menu.

我不小心改了字体，所以不得不快速撤销。

I accidentally changed the font, so I had to quickly ___undo it.