You've persuaded your father to agree to one of your requests so I should let well alone in case he changes his mind.

你已经说服你父亲答应你的一个要求，因此我不必再插手了，以免使他改变主意。

youdao

I’d like to point out that even science is a science, and still very few people can do it, let alone do it well.

我想指出的是，即使像科学这门学科，也只是为数不多的人才能从事，能做出贡献的就更少了。

youdao

Hence all the conversions done in EUR or pounds. I am well aware that Austria and Australia are NOT in the same continent, let alone hemisphere.

从此，所有的汇率转化都是用欧元或者英镑的。我非常清楚的意识到奥地利和澳大利亚并不是在一个大陆上，更别提同一个半球了。

youdao

It recognizes that all is not satisfactory, let alone well, in his theater of operations.

CENTERFORSECURITYPOLICY: Two messages for America

More sensibly, they might decide to leave well alone and let the buyer beware.

ECONOMIST: A survey of world trade

All in all, there is no major industrialized economy with universal coverage that has performed as well--let alone better--than the United States in the last decade.

FORBES: Obama's Health Care Reform Tactics