do good

: to do kind or helpful things : to do things that help other people做好事；帮忙

She tried to make the community better by doing good.她努力通过做好事改善社区。
She has done a lot of good in the community.她在社区里做了很多好事。

— see also do-gooder

a : to be useful or helpful有用处；有帮助— used with any, much, some, etc.与any、much、some等词连用

I tried to convince him to change his mind, but it didn't do any good. [=I was unable to convince him]我努力说服他改变主意，但是没有用。
He's been exercising more and it seems to be doing some good.他最近加强了锻炼，这似乎正在起作用。
You can try, but it probably won't do much good.你可以试试，但是很可能没什么用。
It might do a little good.这可能有点用。

b : to be useful to or helpful for someone or something对…有用处；对…有好处

You should exercise more. It might do you (some) good.你应该多锻炼。这可能对你有（些）好处。
Weeding regularly will do your garden good. [=will improve your garden]定期除草对你的花园有好处。
The visit with her grandchildren did her a world/lot of good. = (Brit) The visit with her grandchildren did her a power of good. [=it was very good for her; it made her feel much better and happier]看望孙辈们让她感到非常高兴。

◊ If you do not think that something is helpful, useful, or worth doing, you can ask What good does it do?, What good is it?, What's the good of it?, etc.这有什么用？

What good does it to do to bring an umbrella along [=why bring an umbrella along] if you are only going to leave it in the car?如果你只打算把伞放在车里，那你带伞有什么用？
What good is a college education when you can't get a job after you graduate?如果毕业后找不到工作，那上大学有什么用？
What's the good of working hard if your boss doesn't give you any credit for it?如果老板不予以肯定，努力工作有什么用？
I could try talking to him, but what good would that do/be? He has already made up his mind.我可以设法和他谈谈，但那会有什么用呢？他已经拿定主意了。