That's being ungrateful, and ingratitude is immoral.

这是忘恩负义 是不道德的。

The same free people of Athens who defeated the Persians later treated Miltiades and Themistocles with just such ingratitude.

这是曾战胜过波斯人的自由的雅典人民，也就是后来很不知感激地对待米尔提亚德斯和泰米斯托克利斯的雅典人民。

Never was hospitality more wholehearted than his. Yet in leaving him I couldn't be accused of ingratitude.

待客的态度，从没有像他那么但白真诚。我离开他，我不能说是忘恩负义。

Some of our ingratitude might be eroded.

我们的一些忘恩负义可能会被侵蚀。

Oh, what weakness, what ingratitude was mine!

哦，我是多么软弱， 多么忘恩负义！

He had never seen serious dishonesty or ingratitude.

他从未见过严重的不诚实或忘恩负义。

And human nature, Dr. Watson—the black ingratitude of it all!

而且人类天性， 华生医生——这一切的黑色忘恩负义！

If you and I go around grumbling about ingratitude, who is to blame?

如果你我四处抱怨忘恩负义， 那该怪谁呢？

'Sharper than the serpent's tooth is the ingratitude of children.' Shakespeare. Kenig Lear

“比蛇的牙齿更锋利的是孩子们的忘恩负义。”莎士比亚，Kenig。

That he had, from his birth, displayed no better qualities than treachery, ingratitude, and malice.

从他出生起，他就没有表现出比背叛、忘恩负义和恶意更好的品质。