我还从没听说过十几岁的男孩儿有莫名其妙地消失的，但是回溯到五十年前，病毒还没被发现的时候，女孩子们也很安全。

I haven't heard of teenage boys disappearing, but up until fifty years ago, when the virus was discovered, girls were also safe.

youdao

缺点：（戏的）作规则有时候在许多回溯进程上会执行的不彻底（翻译，需要懂行的、过的朋友指正）角色的等级不平衡。

The Bad: Action elements are sometimes poorly implemented with lots of backtracking; characters can level unevenly.

youdao

That is--maybe this goes back to the -I didn't mention it, but it would apply to the old goldsmith banker story as well.

这也许又要回溯到...,我在前面没有提过,金匠银行家的故事同样适合解说这个问题

耶鲁公开课 - 金融市场课程节选