I think 'Do they have it or not', while not a literal translation, is much less contrived. It is not currently accepted.
"Do they have it, or don't they" ought to be be an acceptable answer. Or put a second "it" among the answers.
"Another correct solution:Do they have or don't they have ?" I suppose there is an extra space before question mark
I used "Do they or don't they have?" I understand why that is incorrect - it is missing an object. But the accepted answers are missing an object, too, so I agree with wyqtor that adding "it" would be less contrived. A complete sentence would never be "Do they have or don't they have?" This could also be easily solved by adding ellipses, as such: "Do they or don't they have..."
Technically, the exact translation, word for word, would be 'They have it, or don't they?'
While i understand adding 'do' to the front, resulting in 'Do they have it, or don't they?', adding an additional 'have it' at the end is complete nonsense. The word 'have it' simply isn't there in the second part of the sentence.
"They have it or they don't have it?" why is this not accepted? Last time I got this one I answered "They have or they don't have?" and it said that was wrong also.
Right now it says the correct answer should be "Do they've or don't they?" which makes no sense to me. Why put "Do they've"?