如果可以回到过去，在我喜欢的时代生活，我不会回到很久以前。

If l could go back in history and live when I liked, I wouldn't go back very far.

youdao

我希望我们可以回到过去。

I wish we could go back.

youdao

他认为终有一天，人类可以飞入未来，也可以回到过去。

He believes that humans will be able to travel into the future and the past one day.

youdao

And if I want to detach it, I just click and drag, and now I can go back and put different puzzle pieces there altogether.

另外，假如我想分离它，我只需要单击并拖动，然后就可以回到过去那个状态,再继续把不同的拼图放到一起。

哈佛公开课 - 计算机科学课程节选