"Good ideas come from many people!"
Translation:Gute Ideen kommen von vielen Leuten!
Possibly this is helpful. I picked this up from a forum so it’s one step north of a rumor but here it is: If you can use „in“ with the source, then use „aus“. If you can’t use „in“ then use „von“.
For example, I can be in Berlin so „Ich komme aus Berlin“. I can’t be in the Strand so „Ich komme vom Strand“.
So this one is ambiguous on my test but it seems like Duo is ambiguous about it too as there is the other exercise with the aus clause first. Can ideas be „in“ people? Well, sorta, but it‘s more like no than yes because an idea being in someone is poetic or metaphorical and grammar rules ignore those (just as poems ignore grammar rules). So that leads me to von. I wonder if von was acceptable in that other exercise. Moving the clause to the front shouldn’t change anything in any grammar rule my 92 days with German have taught me.
Good Question, MumblingMo! I like it!
On the face of it, your suggestion seems almost better than those accepted! But I think the answer must be that "stammen von" means " to originate from" rather than simply "come from". In this case, a lot of good ideas could come from a group of people, but they might not necessarily be the originators of those ideas. Originality is a rare commodity.