While this is very interesting, these are indeed difficult goals to achieve.

虽然这很有意思，这些实际上是非常难于实现的目标。

youdao

These problems are indeed difficult ones, but I am sure they can be solved.

这些问题固然是有些困难，但我相信他们能够解决。

youdao

If you work really is a terrible memories, then it may indeed difficult to erase from the memory.

如果你的工作真的是一段可怕的回忆，那么可能它确实难以从记忆中抹去。

youdao

I think it's very difficult, indeed I think it's impossible, to think of anything you'd want to do forever.

我认为很难，其实我认为不可能，想出一件你希望永远做下去的事。

耶鲁公开课 - 死亡课程节选

Indeed, in addition to finding him very difficult you've probably said, "Why does he have to write like that?" In other words, "Yeah, okay. He's difficult, but isn't he making it more difficult than it needs to be?"

事实上，除了发现他难懂以外，你可能会说，“为什么他要这样写？“，换句话说，“是的，他的思想很难懂，但是他这样写不是让他的思想更难懂了吗？“

耶鲁公开课 - 文学理论导论课程节选

It is indeed difficult to prove climato-sceptics wrong without referring to obscure science work.

FORBES: Local Warming

It is indeed difficult to know a priori what will resonate in the market.

FORBES: Can You Succeed Through Serendipity?

Yes, producing complete maps for the entire globe is indeed a difficult thing to do.

FORBES: Links 10 Dec: The Apple Maps Can Kill Edition