The whole course is a mess. English can move parts of sentences around very easily and have an identical meaning.
Same for Korean. Duolingo really needs some intelligent language processing engine to parse these. Perhaps the development team needs an A.I. or machine learning expert.
Why is there no particle after 우리? Surely this is the subject of the sentence so should be followed by 는 or 가...?
Thanks for making this community grow on a social level. Your comment has been really helpful and full of insight. Please share your wisdom with us again in the nearest future possible.