"there's no such thing as a free lunch" in Chinese (Simplified)
Definition
这个表达的意思是天下没有免费的东西；所有事情都需要付出代价，哪怕表面看不出来。
Usage Notes (Chinese (Simplified))
这是一个通用谚语，用于提醒别人‘好事不会白白得来’。常用于提醒别人不要轻易相信所谓的免费或优惠。
Examples
Remember, there's no such thing as a free lunch; he will expect something in return.
记住，**天下没有免费的午餐**，他会期待你回报。
My father always says there's no such thing as a free lunch when I ask for money.
我父亲总说**天下没有免费的午餐**，当我跟他要钱的时候。
The company offered a gift, but I know there's no such thing as a free lunch.
公司送了个礼物，但我知道**天下没有免费的午餐**。
You really think you can get all those benefits for free? There's no such thing as a free lunch!
你真的以为这些好处都是白来的？**天下没有免费的午餐**！
Every time I see an unbelievable online deal, I remember there's no such thing as a free lunch.
每次看到网上难以置信的优惠，我就会想到**天下没有免费的午餐**。
If they're offering you something at no cost, be careful. There's no such thing as a free lunch in business.
如果有人免费给你东西，要小心。生意场上**天下没有免费的午餐**。