Translation:Is the sky clear or cloudy?
panctuation mark '?' is introduced from English to Japanese. 'This' Japanese sentence can show the same meaning without '?'.
そらははれていますか、くもっていますか。 At end of Japanese sentence, the mark ' 。' is used.
そらははれていますか、（それとも=or）くもっていますか。 the translator omitted the translate of 'or'. Perhaps I assum that s/he thought that this sentence would more natural.
Again, I had a strict Japanese teacher who insisted that it is incomplete as it stands. Near as I can tell it's because you need to include something like それとも to make it clear that you don't know, and it is not something you just found out, which is the other way to use か. It still gets written as two sentences though; it doesn't seem to act as a conjunction (like 'or') at least as we were taught them back in Canada. More like 'otherwise': (not very natural in English) "The sky is cleared?! Otherwise is it clouded over?"
Dunno why azuranyan got downvoted, FugaziDave's sentence "Is it sunny? Cloudy?" should instead be "Is the sky sunny? Is it Cloudy?" in order to be a sentence that is both proper English and tells duolingo exactly what you mean by "it".
Dunno whether the proper sentance gets accepted or not