start from scratch

基本解释

If we have to start from scratch then it all takes time.
如果我们要从头开始，那么这一切需要时间。
Start from scratch: Start with an empty set of conditions and add your own.
从头开始：从一组空的条件开始并添加您自己的条件。
First of all, if you slip up and damage your reputation at one, you’ll have to start from scratch somewhere else.
首先，如果你犯了错并且马上损害到你的名声，你就不得不在别的什么地方从头开始。

He says the prime minister should declare Japan will not goby the 2006 agreement and will start negotiations from scratch.
and we had to start from scratch together. We did all of our research in the library together.
我们必须从零开始。我们一起在图书馆做研究。
在模拟审判课堂 - SpeakingMax英语口语达人
You're not going to start for the rest of your life if you ever need to solve a problem with a computer from scratch, odds are you're going to reach for some off the shelf packages or libraries or tools that other people wrote so that people like us don't have to reinvent the wheel again and again.
如果你想用Scratch来解决问题,却使用其他人写的程序,或者利用现成的资料或工具,这样以来,我们的确可以避免做重复性的工作,但却永远学不会编程。
哈佛公开课 - 计算机科学课程节选

The best places are refugee economies, where people have had to start from scratch.
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