Given is a literal translation, but usually you would say something like, "Everybody knows that!" Unless there is a shade of meaning that I am missing.
There isn’t. The translation is just awful.
A better one would be ‘it’s common knowledge’.
'This is known to all' wasn't accepted. It's a perfectly fine English sentence and equivalent in translation to 'everyone'.
In other similar exercises, DL accepts the active-voice equivalents which are more commonly used in English, but it wouldn't accept 'Everyone knows this.' I really think it should.
"This is known to all" should be accepted. I have to say you haven't put enough effort in the last few lessons I've done, it's ❤❤❤❤.