It stands to reason that if you are considerate and friendly to people you will get a lot more back.

显然，如果你通情达理、对人友善，你会得到比你付出的多得多的回报。

《柯林斯英汉双解大词典》

If they did know what we made, perhaps they wouldn't be so friendly.

如果他们真的知道我们做了什么，也许他们就不会这么友好了。

youdao

They're almost as friendly as dogs—if you know how to get on with them.

他们几乎和狗一样友好——如果你知道怎么和他们相处的话。

youdao

If you want people to see you as warm and friendly, she says,just smile.

VOA: special.2009.11.24

"That was reassuring, but it also meant that if you were unidentified you had potential friendly fire not too far away at a moment's notice."

VOA: standard.2010.04.06

On November 23rd the government said private insurers could enter the market and that foreign insurers could buy stakes of up to 26% in them (and increase their influence to 40% if friendly institutional funds or overseas Indians invest alongside).

ECONOMIST: Premium market

But I wonder if they are that environmentally friendly if mercury ends up in our landfills and groundwater.

NPR: Letters: Zarif, the Dentist's Chair, and CFL Bulbs

If the friendly and polite approach doesn't work, you could call the Salt Lake Valley Health Department.

WSJ: How to Handle Messy Neighbors