Why not 'the poor countries'?
I think "the poor countries" is incorrect here. You wouldn't use the definite article in English in this context, even though it's the literal translation.
(But it's true that Duolingo is fairly inconsistent on whether it wants the literal or 'right' translation.)
Omg what a nice exercise, no ovono ❤❤❤❤❤❤❤❤, no 3 clauses, correct English etc. I am so delighted I have to highlight it!