I would be an ungrateful wretch if I didn't tell you at least once that it was you who brought some meaning back into my life.

如果我一次也不跟您说：是您给我的生命带来了新的意义，那我可就是个忘恩负义的坏蛋了。

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He's an ungrateful so-and-so.

他是个忘恩负义的家伙。

《牛津词典》

"I'm an ungrateful beast, I know," sobbed Toad, shedding bitter tears.

“我知道，我是个忘恩负义的畜生。”癞蛤蟆托德抽泣着，流下了苦涩的眼泪。

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"This kind of argument, defaming North Korea as an ungrateful scoundrel, intends to do nothing but alienate the relationship between China and North Korea, " Cao Shigong writes in Global Times.

BBC: China media: North Korea sanctions

Peter Wright QC, prosecuting, described Seddon as the ultimate "ungrateful son" who had an "insatiable thirst for cash".

BBC: Stephen Seddon guilty of murdering parents in Sale

And there's still an attitude that young people are "ungrateful", she believes.

BBC: Have young people never had it so bad?